如何使用JSP页面中的参数运行Java类? [英] How do I run a java class with arguments from a JSP page?

问题描述

我以前编写了一个从bash文件执行的Java类，现在我需要使用Javascript/HTML按钮从JSP页面执行该类，我想知道该怎么做?

I have previously written a java class that was executed from a bash file, now I need to allow its execution from a JSP page using a Javascript/HTML button, I wonder how do I do that?

首先，我的课看起来像这样:

First, my class looks like this:

 public class Sync
 {
   public static void main(String[] args)
   {
   //my content here
   }
 }

此Sync类已通过bash脚本运行，如下所示:

This Sync class has been run from a bash script as follows:

cd /root/tomcat/webapps/project/WEB-INF/classes/
echo "Executing first part..."
/usr/local/java/bin/java classes/CLRSyncCLI 120.0.0.1 up false Y ${IPS[@]}
echo "Executing second part..."
/usr/local/java/bin/java classes/CLRSyncCLI 127.0.0.1 down false Y ${IPS[@]}

请注意:classes是TomCat Web服务器中所有已编译的Java类所在的目录.

note that:classes is the directory where all compiled java classes are within the TomCat web server.

现在在jsp页面中，我需要类似的东西:

now within jsp page I need something like:

<input type="button" value="Execute" name="to" action="run" onClick="path here">

如何通过单击一次按钮两次运行此同步类及其参数，并显示该类已执行并显示一条消息.

How do I run this sync classes with its arguments twice from a single button click, and display that the class has been executed with a message.

推荐答案

首先，我想说的是一个不好的主意.您确实应该按照前面的答案中所述重构Sync.

First, I'd like to say what you are proposing is a bad idea. You should really refactor Sync as described in the previous answers.

但是，如果您不愿按原样使用Sync，则下面的一些代码可能会有所帮助:

However, if you are dead-set on using Sync as-is, here is some code that might help:

<% if( request.getParameter( "to" ) == null ) { %>
    <p>
        Click 'Execute' to begin processing.
    </p>
    <form>

        <input type="submit" value="Execute" name="to" />
    </form>
<% } else { %>
    <p>
        Processing...
    </p>
    <pre>
        <%
            PrintStream sysout = System.out;
            try {
                File syncFile = File.createTempFile( "Sync", ".tmp" );

                PrintStream syncOs= new PrintStream( syncFile );
                System.setOut( syncOs );
                String[] myArgs = ...; // set up your args
                Sync.main( myArgs );
                // ... do whatever else you need to do
                syncOs.close();
                syncFile.close();

                FileReader syncRdr = new FileReader( syncFile );
                String line = null;
                while( ( line = syncRdr.readLine() ) {
                    out.println( line );
                }
                syncRdr.close();
                syncFile.delete();
            } catch( Exception ex ) {
                out.print( ex );
            } finally {
                System.setOut( sysout );
            }
        %>
    </pre>
<% } %>

这里有一些潜在的陷阱，尤其是在多线程中.但是也许您可以以此为起点?另外，我尚未调试它，因此您可能需要做更多的工作.

There are some potential pitfalls here, especially with multithreading. But maybe you can use this as a starting point? Also, I have not debugged it, so you might need to do more work.

祝你好运

DC

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