Java调用Http接口(3)--Commons-HttpClient调用Http接口

Commons-HttpClient原来是Apache Commons项目下的一个组件，现已被HttpComponents项目所取代；作为调用Http接口的一种选择，本文介绍下其使用方法。文中所使用到的软件版本：Java 1.8.0_191、Commons-HttpClient 3.1。

1、服务端

参见Java调用Http接口(1)--编写服务端 

2、调用

2.1、GET请求

public static void get() {
    try {
        String requestPath = "http://localhost:8080/webframe/demo/test/getUser?userId=1000&userName=" + URLEncoder.encode("李白", "utf-8");
        HttpClient httpClient = new HttpClient();
        GetMethod get = new GetMethod(requestPath);
        int status = httpClient.executeMethod(get);
        if (status == HttpStatus.SC_OK) {
            System.out.println("GET返回结果：" + get.getResponseBodyAsString());
        } else {
            System.out.println("GET返回状态码：" + status);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

2.2、POST请求(发送键值对数据）

public static void post() {
    try {
        String requestPath = "http://localhost:8080/webframe/demo/test/getUser";
        HttpClient httpClient = new HttpClient();
        PostMethod post = new PostMethod(requestPath);
        post.addRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
        String param = "userId=1000&userName=李白";
        post.setRequestEntity(new StringRequestEntity(param));
        int status = httpClient.executeMethod(post);
        if (status == HttpStatus.SC_OK) {
            System.out.println("POST返回结果：" + post.getResponseBodyAsString());
        } else {
            System.out.println("POST返回状态码：" + status);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

2.3、POST请求(发送JSON数据）

public static void post2() {
    try {
        String requestPath = "http://localhost:8080/webframe/demo/test/addUser";
        HttpClient httpClient = new HttpClient();
        PostMethod post = new PostMethod(requestPath);
        post.addRequestHeader("Content-type", "application/json");
        String param = "{\"userId\": \"1001\",\"userName\":\"杜甫\"}";
        post.setRequestEntity(new StringRequestEntity(param));
        int status = httpClient.executeMethod(post);
        if (status == HttpStatus.SC_OK) {
            System.out.println("POST返回结果：" + post.getResponseBodyAsString());
        } else {
            System.out.println("POST返回状态码：" + status);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

2.4、上传文件及发送键值对数据

public static void multi() {
    try {
        String requestPath = "http://localhost:8080/webframe/demo/test/multi";
        HttpClient httpClient = new HttpClient();
        PostMethod post = new PostMethod(requestPath);

        File file = new File("d:/a.jpg");
        Part[] parts = {new FilePart("file", file), new StringPart("param1", "参数1", "utf-8"), new StringPart("param2", "参数2", "utf-8")};
        
        post.setRequestEntity(new MultipartRequestEntity(parts, post.getParams()));
        int status = httpClient.executeMethod(post);
        if (status == HttpStatus.SC_OK) {
            System.out.println("multi返回结果：" + post.getResponseBodyAsString());
        } else {
            System.out.println("multi返回状态码：" + status);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

2.5、完整例子

package com.inspur.http;

import java.io.File;
import java.net.URLEncoder;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.StringRequestEntity;
import org.apache.commons.httpclient.methods.multipart.FilePart;
import org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity;
import org.apache.commons.httpclient.methods.multipart.Part;
import org.apache.commons.httpclient.methods.multipart.StringPart;

/**
 * 
 * 通过Commons-HttpClient调用Http接口
 *
 */
public class CommonsHttpClientCase {
    /**
     *  GET请求
     */
    public static void get() {
        try {
            String requestPath = "http://localhost:8080/webframe/demo/test/getUser?userId=1000&userName=" + URLEncoder.encode("李白", "utf-8");
            HttpClient httpClient = new HttpClient();
            GetMethod get = new GetMethod(requestPath);
            int status = httpClient.executeMethod(get);
            if (status == HttpStatus.SC_OK) {
                System.out.println("GET返回结果：" + get.getResponseBodyAsString());
            } else {
                System.out.println("GET返回状态码：" + status);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    /**
     *  POST请求(发送键值对数据)
     */
    public static void post() {
        try {
            String requestPath = "http://localhost:8080/webframe/demo/test/getUser";
            HttpClient httpClient = new HttpClient();
            PostMethod post = new PostMethod(requestPath);
            post.addRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
            String param = "userId=1000&userName=李白";
            post.setRequestEntity(new StringRequestEntity(param));
            int status = httpClient.executeMethod(post);
            if (status == HttpStatus.SC_OK) {
                System.out.println("POST返回结果：" + post.getResponseBodyAsString());
            } else {
                System.out.println("POST返回状态码：" + status);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    /**
     *  POST请求(发送json数据)
     */
    public static void post2() {
        try {
            String requestPath = "http://localhost:8080/webframe/demo/test/addUser";
            HttpClient httpClient = new HttpClient();
            PostMethod post = new PostMethod(requestPath);
            post.addRequestHeader("Content-type", "application/json");
            String param = "{\"userId\": \"1001\",\"userName\":\"杜甫\"}";
            post.setRequestEntity(new StringRequestEntity(param));
            int status = httpClient.executeMethod(post);
            if (status == HttpStatus.SC_OK) {
                System.out.println("POST返回结果：" + post.getResponseBodyAsString());
            } else {
                System.out.println("POST返回状态码：" + status);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    /**
     * 上传文件及发送键值对数据
     */
    public static void multi() {
        try {
            String requestPath = "http://localhost:8080/webframe/demo/test/multi";
            HttpClient httpClient = new HttpClient();
            PostMethod post = new PostMethod(requestPath);

            File file = new File("d:/a.jpg");
            Part[] parts = {new FilePart("file", file), new StringPart("param1", "参数1", "utf-8"), new StringPart("param2", "参数2", "utf-8")};
            
            post.setRequestEntity(new MultipartRequestEntity(parts, post.getParams()));
            int status = httpClient.executeMethod(post);
            if (status == HttpStatus.SC_OK) {
                System.out.println("multi返回结果：" + post.getResponseBodyAsString());
            } else {
                System.out.println("multi返回状态码：" + status);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args) {
        get();
        post();
        post2();
        multi();
    }

}

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