How to call the java interface (with code)

java calls the interface method:

package com.lwl.api.provider.demo.test; import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.PrintStream; import java.net.HttpURLConnection; import java.net.URL; public class RestUtil { public String load(String url,String query) throws Exception { URL restURL = new URL(url); /* * 此处的urlConnection对象实际上是根据URL的请求协议(此处是http)生成的URLConnection类 的子类HttpURLConnection */ HttpURLConnection conn = (HttpURLConnection) restURL.openConnection(); //请求方式 conn.setRequestMethod("POST"); //设置是否从httpUrlConnection读入，默认情况下是true; httpUrlConnection.setDoInput(true); conn.setDoOutput(true); //allowUserInteraction 如果为 true，则在允许用户交互（例如弹出一个验证对话框）的上下文中对此 URL 进行检查。 conn.setAllowUserInteraction(false); PrintStream ps = new PrintStream(conn.getOutputStream()); ps.print(query); ps.close(); BufferedReader bReader = new BufferedReader(new InputStreamReader(conn.getInputStream())); String line,resultStr=""; while(null != (line=bReader.readLine())) { resultStr +=line; } System.out.println("接口调用数据："+resultStr); bReader.close(); return resultStr; } public static void main(String []args) {try { RestUtil restUtil = new RestUtil(); String resultString = restUtil.load( "http://192.168.10.89:8080/eoffice-restful/resources/sys/oaholiday", "floor=first&year=2017&month=9&isLeader=N"); } catch (Exception e) { System.out.print(e.getMessage()); } } }

First URL restURL = new URL(url); the url in this is the target interface address that needs to be adjusted, URL Class is a class under java.net.*, which is not unfamiliar.

setRequestMethod("POST"); The request method has two values to choose from, one is GET and the other is POST. Select the corresponding request method

setDoOutput(true);setDoInput(true );

setDoInput() : // Set whether to output to httpUrlConnection. Because this is a post request, the parameters must be placed in the http body, so it needs to be set to true. The default is false;

setDoOutput(): //Set whether to read from httpUrlConnection, which is true by default;

setAllowUserInteraction();allowUserInteraction If true, in a context that allows user interaction (such as popping up a verification dialog box) Check this URL.

The query in the following code is transmitted in the form of attribute=value. If there are multiple queries, it is transmitted in the form of attribute=value&attribute=value. It is passed to the server and let the server handle it by itself.

How to generate this form? The simplest and fastest way is here: Java splices the Map into "parameter = value & parameter = value"

close(); Create a stream to write or read the return value. Remember to close the stream after creation .

For more java knowledge, please pay attention to thejava basic tutorialcolumn.

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