项目总结知识点记录（二）

1.拦截器实现验证用户是否登录：

拦截器类：实现HandlerInterception

package com.yx.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginInterceptor implements HandlerInterceptor  {

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("执行后，返回前执行....");
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        //在处理过程中进行拦截
    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        //已经登录了就放行 否则进行拦截
        HttpSession session=request.getSession();
        if(session.getAttribute("user")!=null){
            return true;//放行
        }else{
            //没有登录 跳转到登录页面进行登录操作
            response.sendRedirect(request.getContextPath()+"/login");
            return false;
        }
    }
}

在SpringMVC.xml文件中注册拦截器：

 2.可以是指项目统一的返回结果：

常量类：

package com.yx.utils;

public class Constants {

    public final static int OK_CODE = 0;    //0表示Ok

    public final static int FAIL_CODE = 400;

    public final static String OK_MSG = "请求成功";

    public final static String FAIL_MSG = "请求失败";

    public final static int STATUS_0 = 0;//可用状态

    public final static int STATUS_1 = 1;//禁用状态

    public final static String CACHE_NAME = "KACache";
}

返回类型实体类：

package com.yx.utils;

import java.io.Serializable;

/**
 * 数据封闭类，返回给前端
 */
public class DataInfo implements Serializable {

    private static final long serialVersionUID = 1L;

    private Integer code;
    private String msg;
    private Object data; //json数据
    private Long count; // 分页信息：总条数

    public DataInfo() {
    }

    public DataInfo(Integer code, String msg, Object data) {
        this.code = code;
        this.msg = msg;
        this.data = data;
    }

    public DataInfo(Integer code, String msg, Object data, Long count) {
        this.code = code;
        this.msg = msg;
        this.data = data;
        this.count = count;
    }

    public Integer getCode() {
        return code;
    }

    public static DataInfo ok() {
        return new DataInfo(Constants.OK_CODE, Constants.OK_MSG, null);
    }

    public static DataInfo ok(Object data) {
        return new DataInfo(Constants.OK_CODE, Constants.OK_MSG, data);
    }

    public static DataInfo ok(String msg, long count, Object data) {
        return new DataInfo(Constants.OK_CODE, Constants.OK_MSG, data,count);
    }

    public static DataInfo ok(String msg, Object data) {
        return new DataInfo(Constants.OK_CODE, msg, data);
    }

    public static DataInfo fail(String msg) {
        return new DataInfo(Constants.FAIL_CODE, msg, null);
    }

    public static DataInfo fail(int errorCode, String msg) {
        return new DataInfo(errorCode, msg, null);
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public Object getData() {
        return data;
    }

    public void setData(Object data) {
        this.data = data;
    }

    public Long getCount() {
        return count;
    }

    public void setCount(Long count) {
        this.count = count;
    }
}

return：返回统一的返回结果 

 

 

 

 3.Spring中放行静态资源：

 4.项目汇总生成验证码：

验证码返回对象：

package com.yx.codeutil;




public class VerifyCode {

    private String code;

    private byte[] imgBytes;

    private long expireTime;

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public byte[] getImgBytes() {
        return imgBytes;
    }

    public void setImgBytes(byte[] imgBytes) {
        this.imgBytes = imgBytes;
    }

    public long getExpireTime() {
        return expireTime;
    }

    public void setExpireTime(long expireTime) {
        this.expireTime = expireTime;
    }
}

接口：

package com.yx.codeutil;

import java.io.IOException;
import java.io.OutputStream;

public interface IVerifyCodeGen {

    /**
     * 生成验证码并返回code，将图片写的os中
     *
     * @param width
     * @param height
     * @param os
     * @return
     * @throws IOException
     */
    String generate(int width, int height, OutputStream os) throws IOException;

    /**
     * 生成验证码对象
     *
     * @param width
     * @param height
     * @return
     * @throws IOException
     */
    VerifyCode generate(int width, int height) throws IOException;
}

实现类：

package com.yx.codeutil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

/**
 * 验证码实现类
 */
public class SimpleCharVerifyCodeGenImpl implements IVerifyCodeGen {

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

    private static final String[] FONT_TYPES = { "\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66" };

    private static final int VALICATE_CODE_LENGTH = 4;

    /**
     * 设置背景颜色及大小，干扰线
     *
     * @param graphics
     * @param width
     * @param height
     */
    private static void fillBackground(Graphics graphics, int width, int height) {
        // 填充背景
        graphics.setColor(Color.WHITE);
        //设置矩形坐标x y 为0
        graphics.fillRect(0, 0, width, height);

        // 加入干扰线条
        for (int i = 0; i < 8; i++) {
            //设置随机颜色算法参数
            graphics.setColor(RandomUtils.randomColor(40, 150));
            Random random = new Random();
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            graphics.drawLine(x, y, x1, y1);
        }
    }

    /**
     * 生成随机字符
     *
     * @param width
     * @param height
     * @param os
     * @return
     * @throws IOException
     */
    @Override
    public String generate(int width, int height, OutputStream os) throws IOException {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics graphics = image.getGraphics();
        fillBackground(graphics, width, height);
        String randomStr = RandomUtils.randomString(VALICATE_CODE_LENGTH);
        createCharacter(graphics, randomStr);
        graphics.dispose();
        //设置JPEG格式
        ImageIO.write(image, "JPEG", os);
        return randomStr;
    }

    /**
     * 验证码生成
     *
     * @param width
     * @param height
     * @return
     */
    @Override
    public VerifyCode generate(int width, int height) {
        VerifyCode verifyCode = null;
        try (
                //将流的初始化放到这里就不需要手动关闭流
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ) {
            String code = generate(width, height, baos);
            verifyCode = new VerifyCode();
            verifyCode.setCode(code);
            verifyCode.setImgBytes(baos.toByteArray());
        } catch (IOException e) {
            logger.error(e.getMessage(), e);
            verifyCode = null;
        }
        return verifyCode;
    }

    /**
     * 设置字符颜色大小
     *
     * @param g
     * @param randomStr
     */
    private void createCharacter(Graphics g, String randomStr) {
        char[] charArray = randomStr.toCharArray();
        for (int i = 0; i < charArray.length; i++) {
            //设置RGB颜色算法参数
            g.setColor(new Color(50 + RandomUtils.nextInt(100),
                    50 + RandomUtils.nextInt(100), 50 + RandomUtils.nextInt(100)));
            //设置字体大小，类型
            g.setFont(new Font(FONT_TYPES[RandomUtils.nextInt(FONT_TYPES.length)], Font.BOLD, 26));
            //设置x y 坐标
            g.drawString(String.valueOf(charArray[i]), 15 * i + 5, 19 + RandomUtils.nextInt(8));
        }
    }
}

生成随机数工具类：

package com.yx.codeutil;

import java.awt.*;
import java.util.Random;

public class RandomUtils extends org.apache.commons.lang3.RandomUtils {

    private static final char[] CODE_SEQ = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J',
            'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
            'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };

    private static final char[] NUMBER_ARRAY = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };

    private static Random random = new Random();

    public static String randomString(int length) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < length; i++) {
            sb.append(String.valueOf(CODE_SEQ[random.nextInt(CODE_SEQ.length)]));
        }
        return sb.toString();
    }

    public static String randomNumberString(int length) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < length; i++) {
            sb.append(String.valueOf(NUMBER_ARRAY[random.nextInt(NUMBER_ARRAY.length)]));
        }
        return sb.toString();
    }

    public static Color randomColor(int fc, int bc) {
        int f = fc;
        int b = bc;
        Random random = new Random();
        if (f > 255) {
            f = 255;
        }
        if (b > 255) {
            b = 255;
        }
        return new Color(f + random.nextInt(b - f), f + random.nextInt(b - f), f + random.nextInt(b - f));
    }

    public static int nextInt(int bound) {
        return random.nextInt(bound);
    }
}

生成验证码接口：

 /**
     * 获取验证码方法
     * @param request
     * @param response
     */
    @RequestMapping("/verifyCode")
    public void verifyCode(HttpServletRequest request, HttpServletResponse response) {
        IVerifyCodeGen iVerifyCodeGen = new SimpleCharVerifyCodeGenImpl();
        try {
            //设置长宽
            VerifyCode verifyCode = iVerifyCodeGen.generate(80, 28);
            String code = verifyCode.getCode();
            //将VerifyCode绑定session
            request.getSession().setAttribute("VerifyCode", code);
            //设置响应头
            response.setHeader("Pragma", "no-cache");
            //设置响应头
            response.setHeader("Cache-Control", "no-cache");
            //在代理服务器端防止缓冲
            response.setDateHeader("Expires", 0);
            //设置响应内容类型
            response.setContentType("image/jpeg");
            response.getOutputStream().write(verifyCode.getImgBytes());
            response.getOutputStream().flush();
        } catch (IOException e) {
            System.out.println("异常处理");
        }
    }

用户登录验证接口：

/**
     * 登录验证
     */
    @RequestMapping("/loginIn")
    public String loginIn(HttpServletRequest request, Model model){
        //获取用户名与密码
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String code=request.getParameter("captcha");
        String type=request.getParameter("type");

        //判断验证码是否正确（验证码已经放入session）
        HttpSession session = request.getSession();
        String realCode = (String)session.getAttribute("VerifyCode");
        if (!realCode.toLowerCase().equals(code.toLowerCase())){
            model.addAttribute("msg","验证码不正确");
            return "login";
        }else{
            //验证码正确则判断用户名和密码
            if(type.equals("1")){//管理员信息
                //用户名和密码是否正确
                Admin admin=adminService.queryUserByNameAndPassword(username,password);
                if(admin==null){//该用户不存在
                    model.addAttribute("msg","用户名或密码错误");
                    return "login";
                }
                session.setAttribute("user",admin);
                session.setAttribute("type","admin");
            }else{//来自读者信息表
                ReaderInfo readerInfo=readerService.queryUserInfoByNameAndPassword(username,password);
                if(readerInfo==null){
                    model.addAttribute("msg","用户名或密码错误");
                    return "login";
                }
                session.setAttribute("user",readerInfo);
                session.setAttribute("type","reader");
            }

            return "index";
        }
    }