java - 如何将值从java传递给PHP？

Question

我正在尝试将值从 java 类传递到服务器上的 PHP 文件以测试该值并回复 java.lang.它返回空值的问题。

Java代码

package phpJava;
import java.io.*;
import java.net.URL;
import javax.swing.JOptionPane;
public class phpbirgde {
public static void main(String[] args) {
        try{
            String erg = JOptionPane.showInputDialog("2+3");
            BufferedReader br = new BufferedReader(new InputStreamReader(new URL("http://localhost//test.php?test="+erg).openStream()));
                    String b = br.readLine();
                    System.out.println(b); // print the string b
                    if(b.equalsIgnoreCase("true")){
                        System.out.println("It is true");
                    }
                    else {
                        System.out.println("False");
                    }

            } catch(IOException e){
                System.out.println("error");
            }
}

    }

PHP代码

 <?php
 $test = $_GET['test'];
 if($test =="5"){
 echo "true";
 }
 else {
 echo "false";
}
?>

Answer 1

由contract :

public String readLine() throws IOException

Reads a line of text. A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

Returns:

A String containing the contents of the line, not including any line-termination characters, or null if the end of the stream has been reached

在你的例子中，php 脚本只是将 true 字符串(没有 \n)输出到输出流中并关闭连接。

因此，在PHP端添加\n (echo "true\n";)，或者使用其他方法从Java端读取响应。