java實現向服務端發送GET和POST請求

 
package com.hongyuan.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
public class HttpClient {
    //發送一個GET請求
    public static String get(String path) throws Exception{
        HttpURLConnection httpConn=null;
        BufferedReader in=null;
        try {
            URL url=new URL(path);
            httpConn=(HttpURLConnection)url.openConnection();

        //讀取響應
        if(httpConn.getResponseCode()==HttpURLConnection.HTTP_OK){
            StringBuffer content=new StringBuffer();
            String tempStr="";
            in=new BufferedReader(new InputStreamReader(httpConn.getInputStream()));
            while((tempStr=in.readLine())!=null){
                content.append(tempStr);
            }
            return content.toString();
        }else{
            throw new Exception("請求出現了問題!");
        }
    } catch (IOException e) {
        e.printStackTrace();
    }finally{
        in.close();
        httpConn.disconnect();
    }
    return null;
}
//發送一個GET請求,參數形式key1=value1&key2=value2...
public static String post(String path,String params) throws Exception{
    HttpURLConnection httpConn=null;
    BufferedReader in=null;
    PrintWriter out=null;
    try {
        URL url=new URL(path);
        httpConn=(HttpURLConnection)url.openConnection();
        httpConn.setRequestMethod("POST");
        httpConn.setDoInput(true);
        httpConn.setDoOutput(true);

        //發送post請求參數
        out=new PrintWriter(httpConn.getOutputStream());
        out.println(params);
        out.flush();

        //讀取響應
        if(httpConn.getResponseCode()==HttpURLConnection.HTTP_OK){
            StringBuffer content=new StringBuffer();
            String tempStr="";
            in=new BufferedReader(new InputStreamReader(httpConn.getInputStream()));
            while((tempStr=in.readLine())!=null){
                content.append(tempStr);
            }
            return content.toString();
        }else{
            throw new Exception("請求出現了問題!");
        }
    } catch (IOException e) {
        e.printStackTrace();
    }finally{
        in.close();
        out.close();
        httpConn.disconnect();
    }
    return null;
}

public static void main(String[] args) throws Exception {
    //String resMessage=HttpClient.get("http://localhost:3000/hello?hello=hello get");
    String resMessage=HttpClient.post("http://localhost:3000/hello", "hello=hello post");
    System.out.println(resMessage);
}


}
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