接上文，百度人脸识别 官方工具类 和好用的类分享 Base64Util FileUtil GsonUtils HttpUtil

1. 给大家直接上一波代码

这是百度官方给的Base64Util,因为官方文档在调用API的示例中给出的图片形式参数为face_token(针对每张图片在图片库中给予编号)，笔者在找了很久如何获取该照片的face_token码后选择了放弃。。。。（）因为真的很不好弄，所以无奈之下选择了将图片转为Base64码，你可以将Base64码理解为 一个txt文档，你看的时候是文字形式，但它也可以转为二进制形式一样，每张不同的图片，通过特定的算法，都有其固定的Base64码，相当于对.jpg/.png格式文件的一份转码，而且是特定的转码（可能因为算法不同，产生的Base64码不一样），但大部分仍然相同

Base64Util.java

package com.baidu.ai.aip.utils;

/**
 * Base64 工具类
 */
public class Base64Util {
    private static final char last2byte = (char) Integer.parseInt("00000011", 2);
    private static final char last4byte = (char) Integer.parseInt("00001111", 2);
    private static final char last6byte = (char) Integer.parseInt("00111111", 2);
    private static final char lead6byte = (char) Integer.parseInt("11111100", 2);
    private static final char lead4byte = (char) Integer.parseInt("11110000", 2);
    private static final char lead2byte = (char) Integer.parseInt("11000000", 2);
    private static final char[] encodeTable = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};

    public Base64Util() {
    }

    public static String encode(byte[] from) {
        StringBuilder to = new StringBuilder((int) ((double) from.length * 1.34D) + 3);
        int num = 0;
        char currentByte = 0;

        int i;
        for (i = 0; i < from.length; ++i) {
            for (num %= 8; num < 8; num += 6) {
                switch (num) {
                    case 0:
                        currentByte = (char) (from[i] & lead6byte);
                        currentByte = (char) (currentByte >>> 2);
                    case 1:
                    case 3:
                    case 5:
                    default:
                        break;
                    case 2:
                        currentByte = (char) (from[i] & last6byte);
                        break;
                    case 4:
                        currentByte = (char) (from[i] & last4byte);
                        currentByte = (char) (currentByte << 2);
                        if (i + 1 < from.length) {
                            currentByte = (char) (currentByte | (from[i + 1] & lead2byte) >>> 6);
                        }
                        break;
                    case 6:
                        currentByte = (char) (from[i] & last2byte);
                        currentByte = (char) (currentByte << 4);
                        if (i + 1 < from.length) {
                            currentByte = (char) (currentByte | (from[i + 1] & lead4byte) >>> 4);
                        }
                }

                to.append(encodeTable[currentByte]);
            }
        }

        if (to.length() % 4 != 0) {
            for (i = 4 - to.length() % 4; i > 0; --i) {
                to.append("=");
            }
        }

        return to.toString();
    }
}

但是它这个类，我根本没搞懂怎么用（可能是笔者太菜了），因为我根本不知道怎么传参，也许百度的原义是通过你对这个的学习，搞懂怎么弄，然后自己重写方法。然而，对于笔者这种面向百度编程的人来说，这根本不可能：）所以我给大家再贴一个类：

Base64ImageUtils.java

package com.test;




import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
 * Created by zhangwenchao on 2017/9/29.
 * 本地或者网络图片资源转为Base64字符串
 */
public class Base64ImageUtils {
    /**
     * @Title: GetImageStrFromUrl
     * @Description: 将一张网络图片转化成Base64字符串
     * @param imgURL 网络资源位置
     * @return Base64字符串
     */
    public static String GetImageStrFromUrl(String imgURL) {
        byte[] data = null;
        try {
            // 创建URL
            URL url = new URL(imgURL);
            // 创建链接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5 * 1000);
            InputStream inStream = conn.getInputStream();
            data = new byte[inStream.available()];
            inStream.read(data);
            inStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        // 返回Base64编码过的字节数组字符串
        return encoder.encode(data);
    }

    /**
     * @Title: GetImageStrFromPath
     * @Description: (将一张本地图片转化成Base64字符串)
     * @param imgPath
     * @return
     */
    public static String GetImageStrFromPath(String imgPath) {
        InputStream in = null;
        byte[] data = null;
        // 读取图片字节数组
        try {
            in = new FileInputStream(imgPath);
            data = new byte[in.available()];
            in.read(data);
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        // 返回Base64编码过的字节数组字符串
        return encoder.encode(data);
    }

    /**
     * @Title: GenerateImage
     * @Description: base64字符串转化成图片
     * @param imgStr
     * @param imgFilePath  图片文件名，如“E:/tmp.jpg”
     * @return
     */
    public static boolean saveImage(String imgStr,String imgFilePath) {
        if (imgStr == null) // 图像数据为空
            return false;
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            // Base64解码
            byte[] b = decoder.decodeBuffer(imgStr);
            for (int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {// 调整异常数据
                    b[i] += 256;
                }
            }
            // 生成jpeg图片
            OutputStream out = new FileOutputStream(imgFilePath);
            out.write(b);
            out.flush();
            out.close();
            return true;
        } catch (Exception e) {
            return false;
        }
    }
}

功能齐全，极其好用，强推，来自于网络，侵权删

接下来都是百度的工具类

FileUtil.java

package com.baidu.ai.aip.utils;

import java.io.*;

/**
 * 文件读取工具类
 */
public class FileUtil {

    /**
     * 读取文件内容，作为字符串返回
     */
    public static String readFileAsString(String filePath) throws IOException {
        File file = new File(filePath);
        if (!file.exists()) {
            throw new FileNotFoundException(filePath);
        } 

        if (file.length() > 1024 * 1024 * 1024) {
            throw new IOException("File is too large");
        } 

        StringBuilder sb = new StringBuilder((int) (file.length()));
        // 创建字节输入流  
        FileInputStream fis = new FileInputStream(filePath);  
        // 创建一个长度为10240的Buffer
        byte[] bbuf = new byte[10240];  
        // 用于保存实际读取的字节数  
        int hasRead = 0;  
        while ( (hasRead = fis.read(bbuf)) > 0 ) {  
            sb.append(new String(bbuf, 0, hasRead));  
        }  
        fis.close();  
        return sb.toString();
    }

    /**
     * 根据文件路径读取byte[] 数组
     */
    public static byte[] readFileByBytes(String filePath) throws IOException {
        File file = new File(filePath);
        if (!file.exists()) {
            throw new FileNotFoundException(filePath);
        } else {
            ByteArrayOutputStream bos = new ByteArrayOutputStream((int) file.length());
            BufferedInputStream in = null;

            try {
                in = new BufferedInputStream(new FileInputStream(file));
                short bufSize = 1024;
                byte[] buffer = new byte[bufSize];
                int len1;
                while (-1 != (len1 = in.read(buffer, 0, bufSize))) {
                    bos.write(buffer, 0, len1);
                }

                byte[] var7 = bos.toByteArray();
                return var7;
            } finally {
                try {
                    if (in != null) {
                        in.close();
                    }
                } catch (IOException var14) {
                    var14.printStackTrace();
                }

                bos.close();
            }
        }
    }
}

GsonUtils.java

/*
 * Copyright (C) 2017 Baidu, Inc. All Rights Reserved.
 */
package com.baidu.ai.aip.utils;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonParseException;

import java.lang.reflect.Type;

/**
 * Json工具类.
 */
public class GsonUtils {
    private static Gson gson = new GsonBuilder().create();

    public static String toJson(Object value) {
        return gson.toJson(value);
    }

    public static <T> T fromJson(String json, Class<T> classOfT) throws JsonParseException {
        return gson.fromJson(json, classOfT);
    }

    public static <T> T fromJson(String json, Type typeOfT) throws JsonParseException {
        return (T) gson.fromJson(json, typeOfT);
    }
}

HttpUtil.java

package com.baidu.ai.aip.utils;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;

/**
 * http 工具类
 */
public class HttpUtil {

    public static String post(String requestUrl, String accessToken, String params)
            throws Exception {
        String contentType = "application/x-www-form-urlencoded";
        return HttpUtil.post(requestUrl, accessToken, contentType, params);
    }

    public static String post(String requestUrl, String accessToken, String contentType, String params)
            throws Exception {
        String encoding = "UTF-8";
        if (requestUrl.contains("nlp")) {
            encoding = "GBK";
        }
        return HttpUtil.post(requestUrl, accessToken, contentType, params, encoding);
    }

    public static String post(String requestUrl, String accessToken, String contentType, String params, String encoding)
            throws Exception {
        String url = requestUrl + "?access_token=" + accessToken;
        return HttpUtil.postGeneralUrl(url, contentType, params, encoding);
    }

    public static String postGeneralUrl(String generalUrl, String contentType, String params, String encoding)
            throws Exception {
        URL url = new URL(generalUrl);
        // 打开和URL之间的连接
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        // 设置通用的请求属性
        connection.setRequestProperty("Content-Type", contentType);
        connection.setRequestProperty("Connection", "Keep-Alive");
        connection.setUseCaches(false);
        connection.setDoOutput(true);
        connection.setDoInput(true);

        // 得到请求的输出流对象
        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
        out.write(params.getBytes(encoding));
        out.flush();
        out.close();

        // 建立实际的连接
        connection.connect();
        // 获取所有响应头字段
        Map<String, List<String>> headers = connection.getHeaderFields();
        // 遍历所有的响应头字段
        for (String key : headers.keySet()) {
            System.err.println(key + "--->" + headers.get(key));
        }
        // 定义 BufferedReader输入流来读取URL的响应
        BufferedReader in = null;
        in = new BufferedReader(
                new InputStreamReader(connection.getInputStream(), encoding));
        String result = "";
        String getLine;
        while ((getLine = in.readLine()) != null) {
            result += getLine;
        }
        in.close();
        System.err.println("result:" + result);
        return result;
    }
}

啊，终于弄完了，，睡觉睡觉！！！