java常用工具类（从开源项目smartframework项目copy过来备用）

1.数组操作工具类

package org.smart4j.framework.util;

import org.apache.commons.lang.ArrayUtils;

/**
 * 数组操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class ArrayUtil {

    /**
     * 判断数组是否非空
     */
    public static boolean isNotEmpty(Object[] array) {
        return !ArrayUtils.isEmpty(array);
    }

    /**
     * 判断数组是否为空
     */
    public static boolean isEmpty(Object[] array) {
        return ArrayUtils.isEmpty(array);
    }

    /**
     * 连接数组
     */
    public static Object[] concat(Object[] array1, Object[] array2) {
        return ArrayUtils.addAll(array1, array2);
    }

    /**
     * 判断对象是否在数组中
     */
    public static <T> boolean contains(T[] array, T obj) {
        return ArrayUtils.contains(array, obj);
    }
}

2. 转型操作工具类

package org.smart4j.framework.util;

/**
 * 转型操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class CastUtil {

    /**
     * 转为 String 型
     */
    public static String castString(Object obj) {
        return CastUtil.castString(obj, "");
    }

    /**
     * 转为 String 型（提供默认值）
     */
    public static String castString(Object obj, String defaultValue) {
        return obj != null ? String.valueOf(obj) : defaultValue;
    }

    /**
     * 转为 double 型
     */
    public static double castDouble(Object obj) {
        return CastUtil.castDouble(obj, 0);
    }

    /**
     * 转为 double 型（提供默认值）
     */
    public static double castDouble(Object obj, double defaultValue) {
        double doubleValue = defaultValue;
        if (obj != null) {
            String strValue = castString(obj);
            if (StringUtil.isNotEmpty(strValue)) {
                try {
                    doubleValue = Double.parseDouble(strValue);
                } catch (NumberFormatException e) {
                    doubleValue = defaultValue;
                }
            }
        }
        return doubleValue;
    }

    /**
     * 转为 long 型
     */
    public static long castLong(Object obj) {
        return CastUtil.castLong(obj, 0);
    }

    /**
     * 转为 long 型（提供默认值）
     */
    public static long castLong(Object obj, long defaultValue) {
        long longValue = defaultValue;
        if (obj != null) {
            String strValue = castString(obj);
            if (StringUtil.isNotEmpty(strValue)) {
                try {
                    longValue = Long.parseLong(strValue);
                } catch (NumberFormatException e) {
                    longValue = defaultValue;
                }
            }
        }
        return longValue;
    }

    /**
     * 转为 int 型
     */
    public static int castInt(Object obj) {
        return CastUtil.castInt(obj, 0);
    }

    /**
     * 转为 int 型（提供默认值）
     */
    public static int castInt(Object obj, int defaultValue) {
        int intValue = defaultValue;
        if (obj != null) {
            String strValue = castString(obj);
            if (StringUtil.isNotEmpty(strValue)) {
                try {
                    intValue = Integer.parseInt(strValue);
                } catch (NumberFormatException e) {
                    intValue = defaultValue;
                }
            }
        }
        return intValue;
    }

    /**
     * 转为 boolean 型
     */
    public static boolean castBoolean(Object obj) {
        return CastUtil.castBoolean(obj, false);
    }

    /**
     * 转为 boolean 型（提供默认值）
     */
    public static boolean castBoolean(Object obj, boolean defaultValue) {
        boolean booleanValue = defaultValue;
        if (obj != null) {
            booleanValue = Boolean.parseBoolean(castString(obj));
        }
        return booleanValue;
    }

    /**
     * 转为 String[] 型
     */
    public static String[] castStringArray(Object[] objArray) {
        if (objArray == null) {
            objArray = new Object[0];
        }
        String[] strArray = new String[objArray.length];
        if (ArrayUtil.isNotEmpty(objArray)) {
            for (int i = 0; i < objArray.length; i++) {
                strArray[i] = castString(objArray[i]);
            }
        }
        return strArray;
    }

    /**
     * 转为 double[] 型
     */
    public static double[] castDoubleArray(Object[] objArray) {
        if (objArray == null) {
            objArray = new Object[0];
        }
        double[] doubleArray = new double[objArray.length];
        if (!ArrayUtil.isEmpty(objArray)) {
            for (int i = 0; i < objArray.length; i++) {
                doubleArray[i] = castDouble(objArray[i]);
            }
        }
        return doubleArray;
    }

    /**
     * 转为 long[] 型
     */
    public static long[] castLongArray(Object[] objArray) {
        if (objArray == null) {
            objArray = new Object[0];
        }
        long[] longArray = new long[objArray.length];
        if (!ArrayUtil.isEmpty(objArray)) {
            for (int i = 0; i < objArray.length; i++) {
                longArray[i] = castLong(objArray[i]);
            }
        }
        return longArray;
    }

    /**
     * 转为 int[] 型
     */
    public static int[] castIntArray(Object[] objArray) {
        if (objArray == null) {
            objArray = new Object[0];
        }
        int[] intArray = new int[objArray.length];
        if (!ArrayUtil.isEmpty(objArray)) {
            for (int i = 0; i < objArray.length; i++) {
                intArray[i] = castInt(objArray[i]);
            }
        }
        return intArray;
    }

    /**
     * 转为 boolean[] 型
     */
    public static boolean[] castBooleanArray(Object[] objArray) {
        if (objArray == null) {
            objArray = new Object[0];
        }
        boolean[] booleanArray = new boolean[objArray.length];
        if (!ArrayUtil.isEmpty(objArray)) {
            for (int i = 0; i < objArray.length; i++) {
                booleanArray[i] = castBoolean(objArray[i]);
            }
        }
        return booleanArray;
    }
}

3. 类操作工具类

package org.smart4j.framework.util;

import java.net.URL;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 类操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class ClassUtil {

    private static final Logger logger = LoggerFactory.getLogger(ClassUtil.class);

    /**
     * 获取类加载器
     */
    public static ClassLoader getClassLoader() {
        return Thread.currentThread().getContextClassLoader();
    }

    /**
     * 获取类路径
     */
    public static String getClassPath() {
        String classpath = "";
        URL resource = getClassLoader().getResource("");
        if (resource != null) {
            classpath = resource.getPath();
        }
        return classpath;
    }

    /**
     * 加载类（将自动初始化）
     */
    public static Class<?> loadClass(String className) {
        return loadClass(className, true);
    }

    /**
     * 加载类
     */
    public static Class<?> loadClass(String className, boolean isInitialized) {
        Class<?> cls;
        try {
            cls = Class.forName(className, isInitialized, getClassLoader());
        } catch (ClassNotFoundException e) {
            logger.error("加载类出错！", e);
            throw new RuntimeException(e);
        }
        return cls;
    }

    /**
     * 是否为 int 类型（包括 Integer 类型）
     */
    public static boolean isInt(Class<?> type) {
        return type.equals(int.class) || type.equals(Integer.class);
    }

    /**
     * 是否为 long 类型（包括 Long 类型）
     */
    public static boolean isLong(Class<?> type) {
        return type.equals(long.class) || type.equals(Long.class);
    }

    /**
     * 是否为 double 类型（包括 Double 类型）
     */
    public static boolean isDouble(Class<?> type) {
        return type.equals(double.class) || type.equals(Double.class);
    }

    /**
     * 是否为 String 类型
     */
    public static boolean isString(Class<?> type) {
        return type.equals(String.class);
    }
}

4. 编码与解码操作工具类

package org.smart4j.framework.util;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.UUID;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.lang.RandomStringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.smart4j.framework.FrameworkConstant;

/**
 * 编码与解码操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class CodecUtil {

    private static final Logger logger = LoggerFactory.getLogger(CodecUtil.class);

    /**
     * 将 URL 编码
     */
    public static String encodeURL(String str) {
        String target;
        try {
            target = URLEncoder.encode(str, FrameworkConstant.UTF_8);
        } catch (Exception e) {
            logger.error("编码出错！", e);
            throw new RuntimeException(e);
        }
        return target;
    }

    /**
     * 将 URL 解码
     */
    public static String decodeURL(String str) {
        String target;
        try {
            target = URLDecoder.decode(str, FrameworkConstant.UTF_8);
        } catch (Exception e) {
            logger.error("解码出错！", e);
            throw new RuntimeException(e);
        }
        return target;
    }

    /**
     * 将字符串 Base64 编码
     */
    public static String encodeBASE64(String str) {
        String target;
        try {
            target = Base64.encodeBase64URLSafeString(str.getBytes(FrameworkConstant.UTF_8));
        } catch (UnsupportedEncodingException e) {
            logger.error("编码出错！", e);
            throw new RuntimeException(e);
        }
        return target;
    }

    /**
     * 将字符串 Base64 解码
     */
    public static String decodeBASE64(String str) {
        String target;
        try {
            target = new String(Base64.decodeBase64(str), FrameworkConstant.UTF_8);
        } catch (UnsupportedEncodingException e) {
            logger.error("解码出错！", e);
            throw new RuntimeException(e);
        }
        return target;
    }

    /**
     * 将字符串 MD5 加密
     */
    public static String encryptMD5(String str) {
        return DigestUtils.md5Hex(str);
    }

    /**
     * 将字符串 SHA 加密
     */
    public static String encryptSHA(String str) {
        return DigestUtils.sha1Hex(str);
    }

    /**
     * 创建随机数
     */
    public static String createRandom(int count) {
        return RandomStringUtils.randomNumeric(count);
    }

    /**
     * 获取 UUID（32位）
     */
    public static String createUUID() {
        return UUID.randomUUID().toString().replaceAll("-", "");
    }
}

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5. 集合操作工具类

package org.smart4j.framework.util;

import java.util.Collection;
import org.apache.commons.collections.CollectionUtils;

/**
 * 集合操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class CollectionUtil {

    /**
     * 判断集合是否非空
     */
    public static boolean isNotEmpty(Collection<?> collection) {
        return CollectionUtils.isNotEmpty(collection);
    }

    /**
     * 判断集合是否为空
     */
    public static boolean isEmpty(Collection<?> collection) {
        return CollectionUtils.isEmpty(collection);
    }
}

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6. 日期操作工具类

package org.smart4j.framework.util;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 日期操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class DateUtil {

    private static final Logger logger = LoggerFactory.getLogger(DateUtil.class);

    private static final SimpleDateFormat datetimeFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
    private static final SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm:ss");

    /**
     * 格式化日期与时间
     */
    public static String formatDatetime(long timestamp) {
        return datetimeFormat.format(new Date(timestamp));
    }

    /**
     * 格式化日期
     */
    public static String formatDate(long timestamp) {
        return dateFormat.format(new Date(timestamp));
    }

    /**
     * 格式化时间
     */
    public static String formatTime(long timestamp) {
        return timeFormat.format(new Date(timestamp));
    }

    /**
     * 获取当前日期与时间
     */
    public static String getCurrentDatetime() {
        return datetimeFormat.format(new Date());
    }

    /**
     * 获取当前日期
     */
    public static String getCurrentDate() {
        return dateFormat.format(new Date());
    }

    /**
     * 获取当前时间
     */
    public static String getCurrentTime() {
        return timeFormat.format(new Date());
    }

    /**
     * 解析日期与时间
     */
    public static Date parseDatetime(String str) {
        Date date = null;
        try {
            date = datetimeFormat.parse(str);
        } catch (ParseException e) {
            logger.error("解析日期字符串出错！格式：yyyy-MM-dd HH:mm:ss", e);
        }
        return date;
    }

    /**
     * 解析日期
     */
    public static Date parseDate(String str) {
        Date date = null;
        try {
            date = dateFormat.parse(str);
        } catch (ParseException e) {
            logger.error("解析日期字符串出错！格式：yyyy-MM-dd", e);
        }
        return date;
    }

    /**
     * 解析时间
     */
    public static Date parseTime(String str) {
        Date date = null;
        try {
            date = timeFormat.parse(str);
        } catch (ParseException e) {
            logger.error("解析日期字符串出错！格式：HH:mm:ss", e);
        }
        return date;
    }
}

7. 文件操作工具类

package org.smart4j.framework.util;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.smart4j.framework.FrameworkConstant;

/**
 * 文件操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class FileUtil {

    private static final Logger logger = LoggerFactory.getLogger(FileUtil.class);

    /**
     * 创建目录
     */
    public static File createDir(String dirPath) {
        File dir;
        try {
            dir = new File(dirPath);
            if (!dir.exists()) {
                FileUtils.forceMkdir(dir);
            }
        } catch (Exception e) {
            logger.error("创建目录出错！", e);
            throw new RuntimeException(e);
        }
        return dir;
    }

    /**
     * 创建文件
     */
    public static File createFile(String filePath) {
        File file;
        try {
            file = new File(filePath);
            File parentDir = file.getParentFile();
            if (!parentDir.exists()) {
                FileUtils.forceMkdir(parentDir);
            }
        } catch (Exception e) {
            logger.error("创建文件出错！", e);
            throw new RuntimeException(e);
        }
        return file;
    }

    /**
     * 复制目录（不会复制空目录）
     */
    public static void copyDir(String srcPath, String destPath) {
        try {
            File srcDir = new File(srcPath);
            File destDir = new File(destPath);
            if (srcDir.exists() && srcDir.isDirectory()) {
                FileUtils.copyDirectoryToDirectory(srcDir, destDir);
            }
        } catch (Exception e) {
            logger.error("复制目录出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 复制文件
     */
    public static void copyFile(String srcPath, String destPath) {
        try {
            File srcFile = new File(srcPath);
            File destDir = new File(destPath);
            if (srcFile.exists() && srcFile.isFile()) {
                FileUtils.copyFileToDirectory(srcFile, destDir);
            }
        } catch (Exception e) {
            logger.error("复制文件出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 删除目录
     */
    public static void deleteDir(String dirPath) {
        try {
            File dir = new File(dirPath);
            if (dir.exists() && dir.isDirectory()) {
                FileUtils.deleteDirectory(dir);
            }
        } catch (Exception e) {
            logger.error("删除目录出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 删除文件
     */
    public static void deleteFile(String filePath) {
        try {
            File file = new File(filePath);
            if (file.exists() && file.isFile()) {
                FileUtils.forceDelete(file);
            }
        } catch (Exception e) {
            logger.error("删除文件出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 重命名文件
     */
    public static void renameFile(String srcPath, String destPath) {
        File srcFile = new File(srcPath);
        if (srcFile.exists()) {
            File newFile = new File(destPath);
            boolean result = srcFile.renameTo(newFile);
            if (!result) {
                throw new RuntimeException("重命名文件出错！" + newFile);
            }
        }
    }

    /**
     * 将字符串写入文件
     */
    public static void writeFile(String filePath, String fileContent) {
        OutputStream os = null;
        Writer w = null;
        try {
            FileUtil.createFile(filePath);
            os = new BufferedOutputStream(new FileOutputStream(filePath));
            w = new OutputStreamWriter(os, FrameworkConstant.UTF_8);
            w.write(fileContent);
            w.flush();
        } catch (Exception e) {
            logger.error("写入文件出错！", e);
            throw new RuntimeException(e);
        } finally {
            try {
                if (os != null) {
                    os.close();
                }
                if (w != null) {
                    w.close();
                }
            } catch (Exception e) {
                logger.error("释放资源出错！", e);
            }
        }
    }

    /**
     * 获取真实文件名（去掉文件路径）
     */
    public static String getRealFileName(String fileName) {
        return FilenameUtils.getName(fileName);
    }

    /**
     * 判断文件是否存在
     */
    public static boolean checkFileExists(String filePath) {
        return new File(filePath).exists();
    }
}

8. JSON 操作工具类

package org.smart4j.framework.util;

import org.codehaus.jackson.map.ObjectMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * JSON 操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class JsonUtil {

    private static final Logger logger = LoggerFactory.getLogger(JsonUtil.class);

    private static final ObjectMapper objectMapper = new ObjectMapper();

    /**
     * 将 Java 对象转为 JSON 字符串
     */
    public static <T> String toJSON(T obj) {
        String jsonStr;
        try {
            jsonStr = objectMapper.writeValueAsString(obj);
        } catch (Exception e) {
            logger.error("Java 转 JSON 出错！", e);
            throw new RuntimeException(e);
        }
        return jsonStr;
    }

    /**
     * 将 JSON 字符串转为 Java 对象
     */
    public static <T> T fromJSON(String json, Class<T> type) {
        T obj;
        try {
            obj = objectMapper.readValue(json, type);
        } catch (Exception e) {
            logger.error("JSON 转 Java 出错！", e);
            throw new RuntimeException(e);
        }
        return obj;
    }
}

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9. 映射操作工具类

package org.smart4j.framework.util;

import java.util.LinkedHashMap;
import java.util.Map;
import org.apache.commons.collections.MapUtils;

/**
 * 映射操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class MapUtil {

    /**
     * 判断 Map 是否非空
     */
    public static boolean isNotEmpty(Map<?, ?> map) {
        return MapUtils.isNotEmpty(map);
    }

    /**
     * 判断 Map 是否为空
     */
    public static boolean isEmpty(Map<?, ?> map) {
        return MapUtils.isEmpty(map);
    }

    /**
     * 转置 Map
     */
    public static <K, V> Map<V, K> invert(Map<K, V> source) {
        Map<V, K> target = null;
        if (isNotEmpty(source)) {
            target = new LinkedHashMap<V, K>(source.size());
            for (Map.Entry<K, V> entry : source.entrySet()) {
                target.put(entry.getValue(), entry.getKey());
            }
        }
        return target;
    }
}

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10. 对象操作工具类

package org.smart4j.framework.util;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.LinkedHashMap;
import java.util.Map;
import org.apache.commons.beanutils.PropertyUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 对象操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class ObjectUtil {

    private static final Logger logger = LoggerFactory.getLogger(ObjectUtil.class);

    /**
     * 设置成员变量
     */
    public static void setField(Object obj, String fieldName, Object fieldValue) {
        try {
            if (PropertyUtils.isWriteable(obj, fieldName)) {
                PropertyUtils.setProperty(obj, fieldName, fieldValue);
            }
        } catch (Exception e) {
            logger.error("设置成员变量出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 获取成员变量
     */
    public static Object getFieldValue(Object obj, String fieldName) {
        Object propertyValue = null;
        try {
            if (PropertyUtils.isReadable(obj, fieldName)) {
                propertyValue = PropertyUtils.getProperty(obj, fieldName);
            }
        } catch (Exception e) {
            logger.error("获取成员变量出错！", e);
            throw new RuntimeException(e);
        }
        return propertyValue;
    }

    /**
     * 复制所有成员变量
     */
    public static void copyFields(Object source, Object target) {
        try {
            for (Field field : source.getClass().getDeclaredFields()) {
                // 若不为 static 成员变量，则进行复制操作
                if (!Modifier.isStatic(field.getModifiers())) {
                    field.setAccessible(true); // 可操作私有成员变量
                    field.set(target, field.get(source));
                }
            }
        } catch (Exception e) {
            logger.error("复制成员变量出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 通过反射创建实例
     */
    @SuppressWarnings("unchecked")
    public static <T> T newInstance(String className) {
        T instance;
        try {
            Class<?> commandClass = ClassUtil.loadClass(className);
            instance = (T) commandClass.newInstance();
        } catch (Exception e) {
            logger.error("创建实例出错！", e);
            throw new RuntimeException(e);
        }
        return instance;
    }

    /**
     * 获取对象的字段映射（字段名 => 字段值），忽略 static 字段
     */
    public static Map<String, Object> getFieldMap(Object obj) {
        return getFieldMap(obj, true);
    }

    /**
     * 获取对象的字段映射（字段名 => 字段值）
     */
    public static Map<String, Object> getFieldMap(Object obj, boolean isStaticIgnored) {
        Map<String, Object> fieldMap = new LinkedHashMap<String, Object>();
        Field[] fields = obj.getClass().getDeclaredFields();
        for (Field field : fields) {
            if (isStaticIgnored && Modifier.isStatic(field.getModifiers())) {
                continue;
            }
            String fieldName = field.getName();
            Object fieldValue = ObjectUtil.getFieldValue(obj, fieldName);
            fieldMap.put(fieldName, fieldValue);
        }
        return fieldMap;
    }
}

View Code

11. 属性文件操作工具类

package org.smart4j.framework.util;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 属性文件操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class PropsUtil {

    private static final Logger logger = LoggerFactory.getLogger(PropsUtil.class);

    /**
     * 加载属性文件
     */
    public static Properties loadProps(String propsPath) {
        Properties props = new Properties();
        InputStream is = null;
        try {
            if (StringUtil.isEmpty(propsPath)) {
                throw new IllegalArgumentException();
            }
            String suffix = ".properties";
            if (propsPath.lastIndexOf(suffix) == -1) {
                propsPath += suffix;
            }
            is = ClassUtil.getClassLoader().getResourceAsStream(propsPath);
            if (is != null) {
                props.load(is);
            }
        } catch (Exception e) {
            logger.error("加载属性文件出错！", e);
            throw new RuntimeException(e);
        } finally {
            try {
                if (is != null) {
                    is.close();
                }
            } catch (IOException e) {
                logger.error("释放资源出错！", e);
            }
        }
        return props;
    }

    /**
     * 加载属性文件，并转为 Map
     */
    public static Map<String, String> loadPropsToMap(String propsPath) {
        Map<String, String> map = new HashMap<String, String>();
        Properties props = loadProps(propsPath);
        for (String key : props.stringPropertyNames()) {
            map.put(key, props.getProperty(key));
        }
        return map;
    }

    /**
     * 获取字符型属性
     */
    public static String getString(Properties props, String key) {
        String value = "";
        if (props.containsKey(key)) {
            value = props.getProperty(key);
        }
        return value;
    }

    /**
     * 获取字符型属性（带有默认值）
     */
    public static String getString(Properties props, String key, String defalutValue) {
        String value = defalutValue;
        if (props.containsKey(key)) {
            value = props.getProperty(key);
        }
        return value;
    }

    /**
     * 获取数值型属性
     */
    public static int getNumber(Properties props, String key) {
        int value = 0;
        if (props.containsKey(key)) {
            value = CastUtil.castInt(props.getProperty(key));
        }
        return value;
    }

    // 获取数值型属性（带有默认值）
    public static int getNumber(Properties props, String key, int defaultValue) {
        int value = defaultValue;
        if (props.containsKey(key)) {
            value = CastUtil.castInt(props.getProperty(key));
        }
        return value;
    }

    /**
     * 获取布尔型属性
     */
    public static boolean getBoolean(Properties props, String key) {
        return getBoolean(props, key, false);
    }

    /**
     * 获取布尔型属性（带有默认值）
     */
    public static boolean getBoolean(Properties props, String key, boolean defalutValue) {
        boolean value = defalutValue;
        if (props.containsKey(key)) {
            value = CastUtil.castBoolean(props.getProperty(key));
        }
        return value;
    }

    /**
     * 获取指定前缀的相关属性
     */
    public static Map<String, Object> getMap(Properties props, String prefix) {
        Map<String, Object> kvMap = new LinkedHashMap<String, Object>();
        Set<String> keySet = props.stringPropertyNames();
        if (CollectionUtil.isNotEmpty(keySet)) {
            for (String key : keySet) {
                if (key.startsWith(prefix)) {
                    String value = props.getProperty(key);
                    kvMap.put(key, value);
                }
            }
        }
        return kvMap;
    }
}

View Code

12. 流操作工具类

package org.smart4j.framework.util;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 流操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class StreamUtil {

    private static final Logger logger = LoggerFactory.getLogger(StreamUtil.class);

    /**
     * 将输入流复制到输出流
     */
    public static void copyStream(InputStream inputStream, OutputStream outputStream) {
        try {
            int length;
            byte[] buffer = new byte[4 * 1024];
            while ((length = inputStream.read(buffer, 0, buffer.length)) != -1) {
                outputStream.write(buffer, 0, length);
            }
            outputStream.flush();
        } catch (Exception e) {
            logger.error("复制流出错！", e);
            throw new RuntimeException(e);
        } finally {
            try {
                inputStream.close();
                outputStream.close();
            } catch (Exception e) {
                logger.error("释放资源出错！", e);
            }
        }
    }

    /**
     * 从输入流中获取字符串
     */
    public static String getString(InputStream is) {
        StringBuilder sb = new StringBuilder();
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (Exception e) {
            logger.error("Stream 转 String 出错！", e);
            throw new RuntimeException(e);
        }
        return sb.toString();
    }
}

View Code

13. 字符串操作工具类

package org.smart4j.framework.util;

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.math.NumberUtils;

/**
 * 字符串操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class StringUtil {

    /**
     * 字符串分隔符
     */
    public static final String SEPARATOR = String.valueOf((char) 29);

    /**
     * 判断字符串是否非空
     */
    public static boolean isNotEmpty(String str) {
        return StringUtils.isNotEmpty(str);
    }

    /**
     * 判断字符串是否为空
     */
    public static boolean isEmpty(String str) {
        return StringUtils.isEmpty(str);
    }

    /**
     * 若字符串为空，则取默认值
     */
    public static String defaultIfEmpty(String str, String defaultValue) {
        return StringUtils.defaultIfEmpty(str, defaultValue);
    }

    /**
     * 替换固定格式的字符串（支持正则表达式）
     */
    public static String replaceAll(String str, String regex, String replacement) {
        Pattern p = Pattern.compile(regex);
        Matcher m = p.matcher(str);
        StringBuffer sb = new StringBuffer();
        while (m.find()) {
            m.appendReplacement(sb, replacement);
        }
        m.appendTail(sb);
        return sb.toString();
    }

    /**
     * 是否为数字（整数或小数）
     */
    public static boolean isNumber(String str) {
        return NumberUtils.isNumber(str);
    }

    /**
     * 是否为十进制数（整数）
     */
    public static boolean isDigits(String str) {
        return NumberUtils.isDigits(str);
    }

    /**
     * 将驼峰风格替换为下划线风格
     */
    public static String camelhumpToUnderline(String str) {
        Matcher matcher = Pattern.compile("[A-Z]").matcher(str);
        StringBuilder builder = new StringBuilder(str);
        for (int i = 0; matcher.find(); i++) {
            builder.replace(matcher.start() + i, matcher.end() + i, "_" + matcher.group().toLowerCase());
        }
        if (builder.charAt(0) == '_') {
            builder.deleteCharAt(0);
        }
        return builder.toString();
    }

    /**
     * 将下划线风格替换为驼峰风格
     */
    public static String underlineToCamelhump(String str) {
        Matcher matcher = Pattern.compile("_[a-z]").matcher(str);
        StringBuilder builder = new StringBuilder(str);
        for (int i = 0; matcher.find(); i++) {
            builder.replace(matcher.start() - i, matcher.end() - i, matcher.group().substring(1).toUpperCase());
        }
        if (Character.isUpperCase(builder.charAt(0))) {
            builder.replace(0, 1, String.valueOf(Character.toLowerCase(builder.charAt(0))));
        }
        return builder.toString();
    }

    /**
     * 分割固定格式的字符串
     */
    public static String[] splitString(String str, String separator) {
        return StringUtils.splitByWholeSeparator(str, separator);
    }

    /**
     * 将字符串首字母大写
     */
    public static String firstToUpper(String str) {
        return Character.toUpperCase(str.charAt(0)) + str.substring(1);
    }

    /**
     * 将字符串首字母小写
     */
    public static String firstToLower(String str) {
        return Character.toLowerCase(str.charAt(0)) + str.substring(1);
    }

    /**
     * 转为帕斯卡命名方式（如：FooBar）
     */
    public static String toPascalStyle(String str, String seperator) {
        return StringUtil.firstToUpper(toCamelhumpStyle(str, seperator));
    }

    /**
     * 转为驼峰命令方式（如：fooBar）
     */
    public static String toCamelhumpStyle(String str, String seperator) {
        return StringUtil.underlineToCamelhump(toUnderlineStyle(str, seperator));
    }

    /**
     * 转为下划线命名方式（如：foo_bar）
     */
    public static String toUnderlineStyle(String str, String seperator) {
        str = str.trim().toLowerCase();
        if (str.contains(seperator)) {
            str = str.replace(seperator, "_");
        }
        return str;
    }

    /**
     * 转为显示命名方式（如：Foo Bar）
     */
    public static String toDisplayStyle(String str, String seperator) {
        String displayName = "";
        str = str.trim().toLowerCase();
        if (str.contains(seperator)) {
            String[] words = StringUtil.splitString(str, seperator);
            for (String word : words) {
                displayName += StringUtil.firstToUpper(word) + " ";
            }
            displayName = displayName.trim();
        } else {
            displayName = StringUtil.firstToUpper(str);
        }
        return displayName;
    }
}

14. Web 操作工具类

package org.smart4j.framework.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.FilenameUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.smart4j.framework.FrameworkConstant;

/**
 * Web 操作工具类
 *
 * @author huangyong
 * @since 1.0
 */
public class WebUtil {

    private static final Logger logger = LoggerFactory.getLogger(WebUtil.class);

    /**
     * 将数据以 JSON 格式写入响应中
     */
    public static void writeJSON(HttpServletResponse response, Object data) {
        try {
            // 设置响应头
            response.setContentType("application/json"); // 指定内容类型为 JSON 格式
            response.setCharacterEncoding(FrameworkConstant.UTF_8); // 防止中文乱码
            // 向响应中写入数据
            PrintWriter writer = response.getWriter();
            writer.write(JsonUtil.toJSON(data)); // 转为 JSON 字符串
            writer.flush();
            writer.close();
        } catch (Exception e) {
            logger.error("在响应中写数据出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 将数据以 HTML 格式写入响应中（在 JS 中获取的是 JSON 字符串，而不是 JSON 对象）
     */
    public static void writeHTML(HttpServletResponse response, Object data) {
        try {
            // 设置响应头
            response.setContentType("text/html"); // 指定内容类型为 HTML 格式
            response.setCharacterEncoding(FrameworkConstant.UTF_8); // 防止中文乱码
            // 向响应中写入数据
            PrintWriter writer = response.getWriter();
            writer.write(JsonUtil.toJSON(data)); // 转为 JSON 字符串
            writer.flush();
            writer.close();
        } catch (Exception e) {
            logger.error("在响应中写数据出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 从请求中获取所有参数（当参数名重复时，用后者覆盖前者）
     */
    public static Map<String, Object> getRequestParamMap(HttpServletRequest request) {
        Map<String, Object> paramMap = new LinkedHashMap<String, Object>();
        try {
            String method = request.getMethod();
            if (method.equalsIgnoreCase("put") || method.equalsIgnoreCase("delete")) {
                String queryString = CodecUtil.decodeURL(StreamUtil.getString(request.getInputStream()));
                if (StringUtil.isNotEmpty(queryString)) {
                    String[] qsArray = StringUtil.splitString(queryString, "&");
                    if (ArrayUtil.isNotEmpty(qsArray)) {
                        for (String qs : qsArray) {
                            String[] array = StringUtil.splitString(qs, "=");
                            if (ArrayUtil.isNotEmpty(array) && array.length == 2) {
                                String paramName = array[0];
                                String paramValue = array[1];
                                if (checkParamName(paramName)) {
                                    if (paramMap.containsKey(paramName)) {
                                        paramValue = paramMap.get(paramName) + StringUtil.SEPARATOR + paramValue;
                                    }
                                    paramMap.put(paramName, paramValue);
                                }
                            }
                        }
                    }
                }
            } else {
                Enumeration<String> paramNames = request.getParameterNames();
                while (paramNames.hasMoreElements()) {
                    String paramName = paramNames.nextElement();
                    if (checkParamName(paramName)) {
                        String[] paramValues = request.getParameterValues(paramName);
                        if (ArrayUtil.isNotEmpty(paramValues)) {
                            if (paramValues.length == 1) {
                                paramMap.put(paramName, paramValues[0]);
                            } else {
                                StringBuilder paramValue = new StringBuilder("");
                                for (int i = 0; i < paramValues.length; i++) {
                                    paramValue.append(paramValues[i]);
                                    if (i != paramValues.length - 1) {
                                        paramValue.append(StringUtil.SEPARATOR);
                                    }
                                }
                                paramMap.put(paramName, paramValue.toString());
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            logger.error("获取请求参数出错！", e);
            throw new RuntimeException(e);
        }
        return paramMap;
    }

    private static boolean checkParamName(String paramName) {
        return !paramName.equals("_"); // 忽略 jQuery 缓存参数
    }

    /**
     * 转发请求
     */
    public static void forwardRequest(String path, HttpServletRequest request, HttpServletResponse response) {
        try {
            request.getRequestDispatcher(path).forward(request, response);
        } catch (Exception e) {
            logger.error("转发请求出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 重定向请求
     */
    public static void redirectRequest(String path, HttpServletRequest request, HttpServletResponse response) {
        try {
            response.sendRedirect(request.getContextPath() + path);
        } catch (Exception e) {
            logger.error("重定向请求出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 发送错误代码
     */
    public static void sendError(int code, String message, HttpServletResponse response) {
        try {
            response.sendError(code, message);
        } catch (Exception e) {
            logger.error("发送错误代码出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 判断是否为 AJAX 请求
     */
    public static boolean isAJAX(HttpServletRequest request) {
        return request.getHeader("X-Requested-With") != null;
    }

    /**
     * 获取请求路径
     */
    public static String getRequestPath(HttpServletRequest request) {
        String servletPath = request.getServletPath();
        String pathInfo = StringUtil.defaultIfEmpty(request.getPathInfo(), "");
        return servletPath + pathInfo;
    }

    /**
     * 从 Cookie 中获取数据
     */
    public static String getCookie(HttpServletRequest request, String name) {
        String value = "";
        try {
            Cookie[] cookieArray = request.getCookies();
            if (cookieArray != null) {
                for (Cookie cookie : cookieArray) {
                    if (StringUtil.isNotEmpty(name) && name.equals(cookie.getName())) {
                        value = CodecUtil.decodeURL(cookie.getValue());
                        break;
                    }
                }
            }
        } catch (Exception e) {
            logger.error("获取 Cookie 出错！", e);
            throw new RuntimeException(e);
        }
        return value;
    }

    /**
     * 下载文件
     */
    public static void downloadFile(HttpServletResponse response, String filePath) {
        try {
            String originalFileName = FilenameUtils.getName(filePath);
            String downloadedFileName = new String(originalFileName.getBytes("GBK"), "ISO8859_1"); // 防止中文乱码

            response.setContentType("application/octet-stream");
            response.addHeader("Content-Disposition", "attachment;filename=\"" + downloadedFileName + "\"");

            InputStream inputStream = new BufferedInputStream(new FileInputStream(filePath));
            OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
            StreamUtil.copyStream(inputStream, outputStream);
        } catch (Exception e) {
            logger.error("下载文件出错！", e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 设置 Redirect URL 到 Session 中
     */
    public static void setRedirectUrl(HttpServletRequest request, String sessionKey) {
        if (!isAJAX(request)) {
            String requestPath = getRequestPath(request);
            request.getSession().setAttribute(sessionKey, requestPath);
        }
    }

    /**
     * 创建验证码
     */
    public static String createCaptcha(HttpServletResponse response) {
        StringBuilder captcha = new StringBuilder();
        try {
            // 参数初始化
            int width = 60;                      // 验证码图片的宽度
            int height = 25;                     // 验证码图片的高度
            int codeCount = 4;                   // 验证码字符个数
            int codeX = width / (codeCount + 1); // 字符横向间距
            int codeY = height - 4;              // 字符纵向间距
            int fontHeight = height - 2;         // 字体高度
            int randomSeed = 10;                 // 随机数种子
            char[] codeSequence = {              // 验证码中可出现的字符
                '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'
            };
            // 创建图像
            BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g = bi.createGraphics();
            // 将图像填充为白色
            g.setColor(Color.WHITE);
            g.fillRect(0, 0, width, height);
            // 设置字体
            g.setFont(new Font("Courier New", Font.BOLD, fontHeight));
            // 绘制边框
            g.setColor(Color.BLACK);
            g.drawRect(0, 0, width - 1, height - 1);
            // 产生随机干扰线（160条）
            g.setColor(Color.WHITE);
            // 创建随机数生成器
            Random random = new Random();
            for (int i = 0; i < 160; i++) {
                int x = random.nextInt(width);
                int y = random.nextInt(height);
                int xl = random.nextInt(12);
                int yl = random.nextInt(12);
                g.drawLine(x, y, x + xl, y + yl);
            }
            // 生成随机验证码
            int red, green, blue;
            for (int i = 0; i < codeCount; i++) {
                // 获取随机验证码
                String validateCode = String.valueOf(codeSequence[random.nextInt(randomSeed)]);
                // 随机构造颜色值
                red = random.nextInt(255);
                green = random.nextInt(255);
                blue = random.nextInt(255);
                // 将带有颜色的验证码绘制到图像中
                g.setColor(new Color(red, green, blue));
                g.drawString(validateCode, (i + 1) * codeX - 6, codeY);
                // 将产生的随机数拼接起来
                captcha.append(validateCode);
            }
            // 禁止图像缓存
            response.setHeader("Cache-Control", "no-store");
            response.setHeader("Pragma", "no-cache");
            response.setDateHeader("Expires", 0);
            // 设置响应类型为 JPEG 图片
            response.setContentType("image/jpeg");
            // 将缓冲图像写到 Servlet 输出流中
            ServletOutputStream sos = response.getOutputStream();
            ImageIO.write(bi, "jpeg", sos);
            sos.close();
        } catch (Exception e) {
            logger.error("创建验证码出错！", e);
            throw new RuntimeException(e);
        }
        return captcha.toString();
    }

    /**
     * 是否为 IE 浏览器
     */
    public boolean isIE(HttpServletRequest request) {
        String agent = request.getHeader("User-Agent");
        return agent != null && agent.contains("MSIE");
    }
}