In this article, let’s take a look at the message interface developed by WeChat
I feel that WeChat development is about calling the WeChat interface, so I will read and try to call the WeChat interface when I have no work arrangements. , calling the WeChat interface requires sending http get and post requests, so it is best to write an httputil class first to specifically send get and post requests. However, my Java network programming is not good, so I Baidu some code and then encapsulate some myself. , it can be used normally. The code is as follows
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
import java.util.Map;
import javax.activation.MimetypesFileTypeMap;
/**
*
* @author luolei
*
*/
public class HttpUtil {
public static String httpGet(String httpUrl){
StringBuffer buffer = null;
try{
URL url = new URL(httpUrl);
HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();
httpUrlConn.setDoInput(true);
httpUrlConn.setRequestMethod("GET");
// 获取输入流
InputStream inputStream = httpUrlConn.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
// 读取返回结果
buffer = new StringBuffer();
String str = null;
while ((str = bufferedReader.readLine()) != null) {
buffer.append(str);
}
// 释放资源
bufferedReader.close();
inputStreamReader.close();
inputStream.close();
httpUrlConn.disconnect();
}catch(Exception e){
e.printStackTrace();
}
return buffer.toString();
}
/**
*
* 发 post 请求，
*/
public static String httpPost(String httpUrl,String data){
PrintWriter out = null;
BufferedReader in = null;
String result = "";
try {
URL realUrl = new URL(httpUrl);
// 打开和URL之间的连接
URLConnection conn = realUrl.openConnection();
// 设置通用的请求属性
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
// 发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
// 获取URLConnection对象对应的输出流
out = new PrintWriter(conn.getOutputStream());
// 发送请求参数
out.print(data);
// flush输出流的缓冲
out.flush();
// 定义BufferedReader输入流来读取URL的响应
in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送 POST 请求出现异常！"+e);
e.printStackTrace();
}
//使用finally块来关闭输出流、输入流
finally{
try{
if(out!=null){
out.close();
}
if(in!=null){
in.close();
}
}
catch(IOException ex){
ex.printStackTrace();
}
}
return result;
}
/**
* 上传图片
*
* @param urlStr
* @param textMap
* @param fileMap
* @return
*/
public static String formUpload(String urlStr, Map textMap,
Map fileMap) {
String res = "";
HttpURLConnection conn = null;
String BOUNDARY = "---------------------------123821742118716"; //boundary就是request头和上传文件内容的分隔符
try {
URL url = new URL(urlStr);
conn = (HttpURLConnection) url.openConnection();
// System.out.println(conn);
conn.setConnectTimeout(5000);
conn.setReadTimeout(30000);
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn
.setRequestProperty("User-Agent",
"Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.6)");
conn.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + BOUNDARY);
OutputStream out = new DataOutputStream(conn.getOutputStream());
// text
if (textMap != null) {
StringBuffer strBuf = new StringBuffer();
Iterator iter = textMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.Entry) iter.next();
String inputName = (String) entry.getKey();
String inputValue = (String) entry.getValue();
if (inputValue == null) {
continue;
}
strBuf.append("\r\n").append("--").append(BOUNDARY).append(
"\r\n");
strBuf.append("Content-Disposition: form-data; name=\""
+ inputName + "\"\r\n\r\n");
strBuf.append(inputValue);
}
out.write(strBuf.toString().getBytes());
}
// file
if (fileMap != null) {
Iterator iter = fileMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.Entry) iter.next();
String inputName = (String) entry.getKey();
String inputValue = (String) entry.getValue();
if (inputValue == null) {
continue;
}
File file = new File(inputValue);
String filename = file.getName();
String contentType = new MimetypesFileTypeMap()
.getContentType(file);
if (filename.endsWith(".png")) {
contentType = "image/png";
}
if (contentType == null || contentType.equals("")) {
contentType = "application/octet-stream";
}
StringBuffer strBuf = new StringBuffer();
strBuf.append("\r\n").append("--").append(BOUNDARY).append(
"\r\n");
strBuf.append("Content-Disposition: form-data; name=\""
+ inputName + "\"; filename=\"" + filename
+ "\"\r\n");
strBuf.append("Content-Type:" + contentType + "\r\n\r\n");
out.write(strBuf.toString().getBytes());
DataInputStream in = new DataInputStream(
new FileInputStream(file));
int bytes = 0;
byte[] bufferOut = new byte[1024];
while ((bytes = in.read(bufferOut)) != -1) {
out.write(bufferOut, 0, bytes);
}
in.close();
}
}
byte[] endData = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();
out.write(endData);
out.flush();
out.close();
// 读取返回数据
StringBuffer strBuf = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
strBuf.append(line).append("\n");
}
res = strBuf.toString();
reader.close();
reader = null;
} catch (Exception e) {
System.out.println("发送POST请求出错。" + urlStr);
e.printStackTrace();
} finally {
if (conn != null) {
conn.disconnect();
conn = null;
}
}
return res;
}
} where httpGet and httpPost are used to send get and post requests. In WeChat development, the message interface is generally in xml format, and the others The data uploaded and returned by the interface is generally json, so a package for parsing json is needed. I use fastjson. Of course, you can also use gson
Now let’s start testing the message interface. First, we need to Understand the request process:
The WeChat server will send a get request based on the filled in URL for verification. When the verification is successful, it will still send a post request based on the URL. The message format is xml format
Message type development document Yes, there are mainly messages such as text, pictures, and voices, as well as some events such as attention, clicks, and jumps.
These messages and events are in xml format, so the messages in xml format need to be parsed. I use dom4j to parse,
The doPost method of the connected servlet is verified before parsing the message,
I followed the method written in Liu Feng's blog and wrote a MessageUtil, which encapsulates the method of parsing xml and puts the parsed results in map
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