有关小程序的JAVA后台解密encryptedData获取openid及用户信息

先贴上工具类，可获取openid及session_key，session_key在解密时会用到，这里还需要用到几个jar包

**bouncycastle-jce-jdk13-112.jar**

**xfire-core-1.2.6.jar**

百度搜一下就有

如果使用maven可以采用以下方法引入

<groupId>bouncycastle</groupId>

<artifactId>bouncycastle-jce-jdk13</artifactId>

</dependency>

<groupId>org.codehaus.xfire</groupId>

<artifactId>xfire-core</artifactId>

</dependency>

GetOpenid.java获取信息工具类

```

package com.hongbao.utils;

import java.io.UnsupportedEncodingException;

import java.security.AlgorithmParameters;

import java.security.InvalidAlgorithmParameterException;

import java.security.InvalidKeyException;

import java.security.NoSuchAlgorithmException;

import java.security.NoSuchProviderException;

import java.security.Security;

import java.security.spec.InvalidParameterSpecException;

import java.util.Arrays;

import javax.crypto.BadPaddingException;

import javax.crypto.Cipher;

import javax.crypto.IllegalBlockSizeException;

import javax.crypto.NoSuchPaddingException;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import org.codehaus.xfire.util.Base64;

import net.sf.json.JSONObject;

/**

* @author silen

* 获取微信信息工具类

public class GetOpenid {

String appid = "wxd81c8f4c18******";

String secret = "7bebc83146c9979ce08d22f244******";

//可获取openid及session_key,其实这里openid不需要获取，encryptedData解密后包含openid

public String get(String js_code) throws Exception {

//官方接口，需要自己提供appid，secret和js_code

String requestUrl = "https://api.weixin.qq.com/sns/jscode2session?appid="+appid+"&secret="+secret+"&js_code="+js_code+"&grant_type=authorization_code";

//HttpRequestor是一个网络请求工具类，贴在了下面

String oppid = new HttpRequestor().doGet(requestUrl);

JSONObject oppidObj = JSONObject.fromObject(oppid);

String openid = (String) oppidObj.get("openid");

String session_key = (String) oppidObj.get("session_key");

return session_key;

}

/**

* 获取信息

public JSONObject getUserInfo(String encryptedData,String sessionkey,String iv){

// 被加密的数据

byte[] dataByte = Base64.decode(encryptedData);

// 加密秘钥

byte[] keyByte = Base64.decode(sessionkey);

// 偏移量

byte[] ivByte = Base64.decode(iv);

try {

// 如果密钥不足16位，那么就补足. 这个if 中的内容很重要

int base = 16;

if (keyByte.length % base != 0) {

int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);

byte[] temp = new byte[groups * base];

Arrays.fill(temp, (byte) 0);

System.arraycopy(keyByte, 0, temp, 0, keyByte.length);

keyByte = temp;

}

// 初始化

Security.addProvider(new BouncyCastleProvider());

Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding","BC");

SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");

AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");

parameters.init(new IvParameterSpec(ivByte));

cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化

byte[] resultByte = cipher.doFinal(dataByte);

if (null != resultByte && resultByte.length > 0) {

String result = new String(resultByte, "UTF-8");

return JSONObject.fromObject(result);

}

} catch (NoSuchAlgorithmException e) {

e.printStackTrace();

} catch (NoSuchPaddingException e) {

e.printStackTrace();

} catch (InvalidParameterSpecException e) {

e.printStackTrace();

} catch (IllegalBlockSizeException e) {

e.printStackTrace();

} catch (BadPaddingException e) {

e.printStackTrace();

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

} catch (InvalidKeyException e) {

e.printStackTrace();

} catch (InvalidAlgorithmParameterException e) {

e.printStackTrace();

} catch (NoSuchProviderException e) {

e.printStackTrace();

}

return null;

}

```

网络请求工具类,在使用官方提供的接口获取信息的时候使用，在上面的类中已经有使用方法，很简单

HttpRequestor.java

```

package com.hongbao.utils;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.net.HttpURLConnection;

import java.net.InetSocketAddress;

import java.net.Proxy;

import java.net.URL;

import java.net.URLConnection;

import java.util.Iterator;

import java.util.Map;

public class HttpRequestor {

private String charset = "utf-8";

private Integer connectTimeout = null;

private Integer socketTimeout = null;

private String proxyHost = null;

private Integer proxyPort = null;

/**

* Do GET request

* @param url

* @return

* @throws Exception

* @throws IOException

public String doGet(String url) throws Exception {

URL localURL = new URL(url);

URLConnection connection = openConnection(localURL);

HttpURLConnection httpURLConnection = (HttpURLConnection)connection;

httpURLConnection.setRequestProperty("Accept-Charset", charset);

httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

InputStream inputStream = null;

InputStreamReader inputStreamReader = null;

BufferedReader reader = null;

StringBuffer resultBuffer = new StringBuffer();

String tempLine = null;

if (httpURLConnection.getResponseCode() >= 300) {

throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());

}

try {

inputStream = httpURLConnection.getInputStream();

inputStreamReader = new InputStreamReader(inputStream,"UTF-8");

reader = new BufferedReader(inputStreamReader);

while ((tempLine = reader.readLine()) != null) {

resultBuffer.append(tempLine);

}

} finally {

if (reader != null) {

reader.close();

}

if (inputStreamReader != null) {

inputStreamReader.close();

}

if (inputStream != null) {

inputStream.close();

}

return resultBuffer.toString();

}

/**

* Do POST request

* @param url

* @param parameterMap

* @return

* @throws Exception

public String doPost(String url, Map parameterMap) throws Exception {

/* Translate parameter map to parameter date string */

StringBuffer parameterBuffer = new StringBuffer();

if (parameterMap != null) {

Iterator iterator = parameterMap.keySet().iterator();

String key = null;

String value = null;

while (iterator.hasNext()) {

key = (String)iterator.next();

if (parameterMap.get(key) != null) {

value = (String)parameterMap.get(key);

} else {

value = "";

}

parameterBuffer.append(key).append("=").append(value);

if (iterator.hasNext()) {

parameterBuffer.append("&");

}

System.out.println("POST parameter : " + parameterBuffer.toString());

URL localURL = new URL(url);

URLConnection connection = openConnection(localURL);

HttpURLConnection httpURLConnection = (HttpURLConnection)connection;

httpURLConnection.setDoOutput(true);

httpURLConnection.setRequestMethod("POST");

httpURLConnection.setRequestProperty("Accept-Charset", charset);

httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

httpURLConnection.setRequestProperty("Content-Length", String.valueOf(parameterBuffer.length()));

OutputStream outputStream = null;

OutputStreamWriter outputStreamWriter = null;

InputStream inputStream = null;

InputStreamReader inputStreamReader = null;

BufferedReader reader = null;

StringBuffer resultBuffer = new StringBuffer();

String tempLine = null;

try {

outputStream = httpURLConnection.getOutputStream();

outputStreamWriter = new OutputStreamWriter(outputStream);

outputStreamWriter.write(parameterBuffer.toString());

outputStreamWriter.flush();

if (httpURLConnection.getResponseCode() >= 300) {

throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());

}

inputStream = httpURLConnection.getInputStream();

inputStreamReader = new InputStreamReader(inputStream);

reader = new BufferedReader(inputStreamReader);

while ((tempLine = reader.readLine()) != null) {

resultBuffer.append(tempLine);

}

} finally {

if (outputStreamWriter != null) {

outputStreamWriter.close();

}

if (outputStream != null) {

outputStream.close();

}

if (reader != null) {

reader.close();

}

if (inputStreamReader != null) {

inputStreamReader.close();

}

if (inputStream != null) {

inputStream.close();

}

return resultBuffer.toString();

}

private URLConnection openConnection(URL localURL) throws IOException {

URLConnection connection;

if (proxyHost != null && proxyPort != null) {

Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPort));

connection = localURL.openConnection(proxy);

} else {

connection = localURL.openConnection();

}

return connection;

}

/**

* Render request according setting

* @param request

private void renderRequest(URLConnection connection) {

if (connectTimeout != null) {

connection.setConnectTimeout(connectTimeout);

}

if (socketTimeout != null) {

connection.setReadTimeout(socketTimeout);

}

* Getter & Setter

public Integer getConnectTimeout() {

return connectTimeout;

}

public void setConnectTimeout(Integer connectTimeout) {

this.connectTimeout = connectTimeout;

}

public Integer getSocketTimeout() {

return socketTimeout;

}

public void setSocketTimeout(Integer socketTimeout) {

this.socketTimeout = socketTimeout;

}

public String getProxyHost() {

return proxyHost;

}

public void setProxyHost(String proxyHost) {

this.proxyHost = proxyHost;

}

public Integer getProxyPort() {

return proxyPort;

}

public void setProxyPort(Integer proxyPort) {

this.proxyPort = proxyPort;

}

public String getCharset() {

return charset;

}

public void setCharset(String charset) {

this.charset = charset;

}

```

controller，这里就是工具类的使用方法了，没什么难度，简单的调用

```

// 获取信息

@ResponseBody

@RequestMapping("getOpenid")

public void getOpenid(HttpServletRequest request,

HttpServletResponse response) throws Exception {

request.setCharacterEncoding("UTF-8");

response.setCharacterEncoding("UTF-8");

//需要使用小程序传过来的js_code获取session_key

String js_code = request.getParameter("js_code");

//这个就是要解密的东西--用户敏感信息加密数据

String encryptedData = request.getParameter("encryptedData");

//加密算法的初始向量

String iv = request.getParameter("iv");

//调用工具类中获取session_key的方法

String sessionkey = new GetOpenid().get(js_code);

//调用工具类中的解密方法，然后返回给小程序就OK了

JSONObject obj = new GetOpenid().getUserInfo(encryptedData, sessionkey,

iv);

Gson gson = new Gson();

String json = gson.toJson(obj);

PrintWriter pw = response.getWriter();

pw.write(json);

pw.close();

}

```

最后是小程序端的请求代码

```

var that = this

wx.login({

success: function (res) {

if (res.code) {

wx.getUserInfo({

success: datas => {

wx.request({

url: that.baseurl + 'getOpenid',

data: {

js_code: res.code,

encryptedData: datas.encryptedData,

iv: datas.iv

header: {

'content-type': 'application/json'

success: function (e) {

console.log(e.data)

}

})

}

})

}

else {

console.log('获取用户登录态失败！' + res.errMsg)

}

})

```

大功告成！！！