我编写了几个简单的 java 应用程序,分别命名为 A.jar、B.jar。
现在我想编写一个 GUI java 程序,以便用户可以按按钮 A 执行 A.jar 和按钮 B 执行 B.jar。
我还想在我的 GUI 程序中输出运行时进程的详细信息。
有什么建议吗?
我编写了几个简单的 java 应用程序,分别命名为 A.jar、B.jar。
现在我想编写一个 GUI java 程序,以便用户可以按按钮 A 执行 A.jar 和按钮 B 执行 B.jar。
我还想在我的 GUI 程序中输出运行时进程的详细信息。
有什么建议吗?
如果我理解正确,您似乎想在 Java GUI 应用程序内部的单独进程中运行 jar。
为此,您可以使用:
// Run a java app in a separate system process
Process proc = Runtime.getRuntime().exec("java -jar A.jar");
// Then retreive the process output
InputStream in = proc.getInputStream();
InputStream err = proc.getErrorStream();
缓冲进程的输出总是好的做法。
.jar 不可执行。实例化类或调用任何静态方法。
编辑:在创建 JAR 时添加主类条目。
>p.mf(p.mf 的内容)
主类:pk.Test
>Test.java
package pk;
public class Test{
public static void main(String []args){
System.out.println("Hello from Test");
}
}
使用 Process 类及其方法,
public class Exec
{
public static void main(String []args) throws Exception
{
Process ps=Runtime.getRuntime().exec(new String[]{"java","-jar","A.jar"});
ps.waitFor();
java.io.InputStream is=ps.getInputStream();
byte b[]=new byte[is.available()];
is.read(b,0,b.length);
System.out.println(new String(b));
}
}
希望这可以帮助:
public class JarExecutor {
private BufferedReader error;
private BufferedReader op;
private int exitVal;
public void executeJar(String jarFilePath, List<String> args) throws JarExecutorException {
// Create run arguments for the
final List<String> actualArgs = new ArrayList<String>();
actualArgs.add(0, "java");
actualArgs.add(1, "-jar");
actualArgs.add(2, jarFilePath);
actualArgs.addAll(args);
try {
final Runtime re = Runtime.getRuntime();
//final Process command = re.exec(cmdString, args.toArray(new String[0]));
final Process command = re.exec(actualArgs.toArray(new String[0]));
this.error = new BufferedReader(new InputStreamReader(command.getErrorStream()));
this.op = new BufferedReader(new InputStreamReader(command.getInputStream()));
// Wait for the application to Finish
command.waitFor();
this.exitVal = command.exitValue();
if (this.exitVal != 0) {
throw new IOException("Failed to execure jar, " + this.getExecutionLog());
}
} catch (final IOException | InterruptedException e) {
throw new JarExecutorException(e);
}
}
public String getExecutionLog() {
String error = "";
String line;
try {
while((line = this.error.readLine()) != null) {
error = error + "\n" + line;
}
} catch (final IOException e) {
}
String output = "";
try {
while((line = this.op.readLine()) != null) {
output = output + "\n" + line;
}
} catch (final IOException e) {
}
try {
this.error.close();
this.op.close();
} catch (final IOException e) {
}
return "exitVal: " + this.exitVal + ", error: " + error + ", output: " + output;
}
}
以下通过使用批处理文件启动 jar 来工作,以防程序作为独立运行:
public static void startExtJarProgram(){
String extJar = Paths.get("C:\\absolute\\path\\to\\batchfile.bat").toString();
ProcessBuilder processBuilder = new ProcessBuilder(extJar);
processBuilder.redirectError(new File(Paths.get("C:\\path\\to\\JavaProcessOutput\\extJar_out_put.txt").toString()));
processBuilder.redirectInput();
try {
final Process process = processBuilder.start();
try {
final int exitStatus = process.waitFor();
if(exitStatus==0){
System.out.println("External Jar Started Successfully.");
System.exit(0); //or whatever suits
}else{
System.out.println("There was an error starting external Jar. Perhaps path issues. Use exit code "+exitStatus+" for details.");
System.out.println("Check also C:\\path\\to\\JavaProcessOutput\\extJar_out_put.txt file for additional details.");
System.exit(1);//whatever
}
} catch (InterruptedException ex) {
System.out.println("InterruptedException: "+ex.getMessage());
}
} catch (IOException ex) {
System.out.println("IOException. Faild to start process. Reason: "+ex.getMessage());
}
System.out.println("Process Terminated.");
System.exit(0);
}
在 batchfile.bat 中,我们可以说:
@echo off
start /min C:\path\to\jarprogram.jar
如果 jar 在您的类路径中,并且您知道它的 Main 类,则可以调用 main 类。以 DITA-OT 为例:
import org.dita.dost.invoker.CommandLineInvoker;
....
CommandLineInvoker.main('-f', 'html5', '-i', 'samples/sequence.ditamap', '-o', 'test')
请注意,这将使从属 jar 与您的 jar 共享内存空间和类路径,并且可能会导致干扰。如果您不希望这些东西被污染,您还有其他选择,如上所述 - 即:
Runtime.getRuntime.exec(...)
(它完全隔离了 jar,但具有正常的“查找应用程序”、“正确转义字符串”、“特定于平台的 WTF”和“OMG 系统线程”运行系统命令的陷阱。首先,我们创建一个 FirstFileOutput 类,该类具有一个 main 方法,该方法输出一行到稳定输出和一行到稳定错误。通过所有第一个过程,我们将再次创建一个 RuntimeExecCheck 类,它将在启动进程时运行我们的 FirstFileOutput 类,之后 RuntimeExecCheck 类将从 FirstFileOutput 读取稳定输出和稳定错误并输出。
package check;
public class FirstFileOutput{
public static void main(String[] args) {
System.out.println("This is output to stable output");
System.err.println("This is output to stable error");
}
}
package check;
import java.io.InputStream;
import java.io.IOException;
import java.io.InputStreamReader;
public class RuntimeExecCheck {
public static void main(String[] args) {
try {
Runtime runTime = Runtime.getRuntime();
Process process = runTime.exec("java -classpath C:\\projects\\workspace\\check\\bin check.FirstFileOutput");
InputStream inputStream = process.getInputStream();
InputStreamReader isr = new InputStreamReader(inputStream);
InputStream errorStream = process.getErrorStream();
InputStreamReader esr = new InputStreamReader(errorStream);
int n1;
char[] c1 = new char[1024];
StringBuffer stableOutput = new StringBuffer();
while ((n1 = isr.read(c1)) > 0) {
stableOutput.append(c1, 0, n1);
}
System.out.println("Stable Output: " + stableOutput.toString());
int n2;
char[] c2 = new char[1024];
StringBuffer stableError = new StringBuffer();
while ((n2 = esr.read(c2)) > 0) {
stableError.append(c2, 0, n2);
}
System.out.println("Stable Error: " + stableError.toString());
} catch (IOException e) {
e.printStackTrace();
}
}
}
如果你是java 1.6,那么也可以进行以下操作:
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
public class CompilerExample {
public static void main(String[] args) {
String fileToCompile = "/Users/rupas/VolatileExample.java";
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
int compilationResult = compiler.run(null, null, null, fileToCompile);
if (compilationResult == 0) {
System.out.println("Compilation is successful");
} else {
System.out.println("Compilation Failed");
}
}
}