Question

我将制作一个毕业项目，Web应用程序将编译java并运行代码。现在我可以编译和运行简单的java代码，如：

public class code{

public static void main(String[] args) {
    System.out.println("Hello, World");
    int a=2;
    int b=3;
    System.out.println(a*b);
}
}

İmages： enter image description here

enter image description here

没关系，但是当代码包含扫描程序以从用户那里获取输入时，我通常无法从用户那里获取输入，因为我只是写输出。我不知道如何编译包含扫描器类的java代码。

FormHandlerServlet.java：

package com.crc64.servlet;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.tools.DiagnosticCollector;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;


@WebServlet("/formhandlerservlet")
public class FormHandlerServlet extends HttpServlet {

 private String title;
 private String docType;

 @Override
 public void init() throws ServletException {
 this.title = "Using GET Method to Read Form Data";
 this.docType = "<!doctype html public \"-//w3c//dtd html 4.0 transitional//en\">";
 }

 @Override
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 doGet(request, response);
 }

 @Override
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 response.setContentType("text/html");
 PrintWriter writer = response.getWriter();
 writer.println(docType);
 writer.println("<html>");
 writer.println("<head>");
 writer.println("<title>");
 //writer.println(title);
 writer.println("</title>");
 writer.println("</head>");
 writer.println("<body bgcolor=\"#f0f0f0\">");
 writer.println("<h1 align=\"center\">");
 //writer.println(title);
 writer.println("</h1>");
 writer.println("<ul>");
 writer.println("<li>");
 writer.println("<b>");
 writer.print("Result:");
 writer.println("</b>");
 writer.println("<br>");
 writer.println("<textarea style=\"width:500px;height:300px;\">");
// writer.println(request.getParameter("x"));

 DosyayaYaz(request.getParameter("x"));





/*JavaCompiler compiler = new JavaCompilerFactory().createCompiler("eclipse");
CompilationResult result = compiler.compile(sources, new FileResourceReader(sourceDir), new FileResourceStore(targetDir));

System.out.println( result.getErrors().length + " errors");
System.out.println( result.getWarnings().length + " warnings");
 */

 System.setProperty("java.home", "C:\\Program Files\\Java\\jdk1.8.0_45");
 JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
 DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<>();
 StandardJavaFileManager fileManager = compiler.getStandardFileManager(diagnostics, null, null);
 Iterable<? extends JavaFileObject> compilationUnits = fileManager.getJavaFileObjectsFromStrings(Arrays.asList("C:\\Users\\ASUS\\workspace\\formservlet\\code.java"));
 JavaCompiler.CompilationTask task = compiler.getTask(null, fileManager, diagnostics, null,
         null, compilationUnits);
 boolean success = task.call();
 fileManager.close();
 int compilationResult = compiler.run(null, null, null, "C:\\Users\\ASUS\\workspace\\formservlet\\code.java");
 //Runtime.getRuntime().exec("java code");
 //Process process = Runtime.getRuntime().exec("code.class");
// Run("code","C:\\Users\\ASUS\\workspace\\formservlet");
 String clasname="code";
 String loc="C:\\Users\\ASUS\\workspace\\formservlet";
 final String dosCommand = "cmd /c java -cp ";
 final String classname = clasname;
 final String location = loc;
 try {
     final Process process = Runtime.getRuntime().exec("cmd /c java -cp " + location + " " + classname);
     final InputStream in = process.getInputStream();
     final InputStream in2 = process.getErrorStream();
     int ch, ch2;
     while ((ch = in.read()) != -1) {
        System.out.print((char) ch);
         writer.print((char) ch);
     }
     while ((ch2 = in2.read()) != -1) {
         System.out.print((char) ch2); // read error here
     }
 } catch (IOException e) {
     e.printStackTrace();
 }

 writer.println("</textarea>");
 /* writer.println("</li>");
  writer.println("<li>");
  writer.println("<b>");
  writer.print("Last Name: ");
  writer.println("</b>");
  writer.println(request.getParameter("x"));
  writer.println("</li>");*/
  writer.println("</ul>");
  writer.println("</body>");
  writer.println("</html>");




 }

 public static void Run(String clasname,String loc){

 }



 private static void DosyayaYaz(String input) throws IOException{
        String path = "C:\\Users\\ASUS\\workspace\\formservlet\\code.java";
        FileWriter file = new FileWriter(path);
        BufferedWriter writer = new BufferedWriter(file);
        writer.write(input);
        writer.close();     
        //System.out.println("Dosya Oluşturuldu");
    }


 private static final long serialVersionUID = 4991957348534606746L;

}

的index.html：

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Get Method Sample</title>
</head>
<body>
 <form action="formhandlerservlet" method="post">

 <label for="Your Code">Your Code :</label><br>
 <textarea for="x" type="text" name="x" style="width:500px;height:300px;"></textarea>
 <input type="submit" value="Compile and Run" />

 </form>
</body>
</html>

最后我应该怎么做才能在运行时使用Scanner Class？

如何在运行时

0 个答案: