在上一篇中我们说了一下如何创建简单的rest api（假期别闲着：REST API实战演练之创建Rest API-CSDN博客），我们创建了那就是为了使用的，下面我们就看看，通过构建一个客户端程序如何使用我们创建的rest api吧。
1、新建一个java项目
Eclipse新建java项目不再赘述。
2、在新项目中引入rest api项目
因为我们在创建restapi的项目的时候没有导出jar包，可以在该项目中直接引入restapi的项目路径，如下图所示：
3、添加Org.json包
下载地址：https://central.sonatype.com/artifact/org.json/json/versions
跳转后下载org.json即可
然后把jar包添加到项目中。
4、创建一个java控制台应用程序
新建一个java项目，创建一个类，勾选复选框，带上创建静态main函数，如下所示：
5、修改代码，添加访问rest api方法
java
package com.restful;
import java.util.Scanner;
import org.json.JSONObject;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
public class DataAccess {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
Scanner scanner = new Scanner(System.in);
System.out.println("Welcome to the Person Info Command Line Editor.");
System.out.println("(PICLER for short.)");
System.out.println("Do you want to get or set a person's info?");
System.out.println("(Type 'get' or 'set' now.)");
String getOrSet = scanner.nextLine();
if("get".equalsIgnoreCase(getOrSet)){
System.out.println("Whose info do you want to get?");
System.out.println("(Type a person's name now.)");
String name = scanner.nextLine();
String jsonString = getPersonData(name);
JSONObject jsonObject = new JSONObject(jsonString);
int birthYear = jsonObject.getInt("birthYear");
System.out.println(name + " was born in " + birthYear + ".");
String about = jsonObject.getString("about");
System.out.println(about);
}
else if("set".equalsIgnoreCase(getOrSet)){
System.out.println("Whose info do you want to set?");
System.out.println("(Type a person's name now.)");
String name = scanner.nextLine();
System.out.println("When was " + name + " born?");
System.out.println("(Type a year now.)");
String birthYear = scanner.nextLine();
System.out.println("Can you tell me about " + name + "?");
System.out.println("(Type a sentence now.)");
String about = scanner.nextLine();
setPersonData(name, birthYear, about);
}
scanner.close();
System.out.println("Thanks for using PICLER.");
}
public static String getPersonData(String name) throws IOException{
HttpURLConnection connection = (HttpURLConnection) new URL("http://localhost:8080/HelloJSP/people/" + name).openConnection();
connection.setRequestMethod("GET");
int responseCode = connection.getResponseCode();
if(responseCode == 200){
String response = "";
Scanner scanner = new Scanner(connection.getInputStream());
while(scanner.hasNextLine()){
response += scanner.nextLine();
response += "\n";
}
scanner.close();
return response;
}
// an error happened
return null;
}
@SuppressWarnings("deprecation")
public static void setPersonData(String name, String birthYear, String about) throws IOException{
HttpURLConnection connection = (HttpURLConnection) new URL("http://localhost:8080/HelloJSP/people/" + name).openConnection();
connection.setRequestMethod("POST");
String postData = "name=" + URLEncoder.encode(name);
postData += "&about=" + URLEncoder.encode(about);
postData += "&birthYear=" + birthYear;
connection.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(connection.getOutputStream());
wr.write(postData);
wr.flush();
int responseCode = connection.getResponseCode();
if(responseCode == 200){
System.out.println("POST was successful.");
}
else if(responseCode == 401){
System.out.println("Wrong password.");
}
}
}6、运行测试
我们写的是一个java控制台应用程序，那么直接运行后在控制台输入信息即可。
运行后，根据提示输入（测试前确保前面的创建rest api是启动着的）：
输入se测试如下：
通过客户端修改后，我们再在浏览器看一下我们修改的数据。
参考资料：