如何执行包含来自不同java程序(runtime.exec())的带有参数的方法的java类文件?
我是这样做的,它给了我类文件,但我不知道如何执行它,因为我想在运行时也传递参数如何执行包含来自不同java程序(runtime.exec())的带有参数的方法的java类文件?,java,class,runtime.exec,Java,Class,Runtime.exec,我是这样做的,它给了我类文件,但我不知道如何执行它,因为我想在运行时也传递参数 package first; import java.io.*; public class RuntimeExec { public static void main(String[] args) { try { // print a message // create a file with the working
package first;
import java.io.*;
public class RuntimeExec {
public static void main(String[] args) {
try {
// print a message
// create a file with the working directory we wish
File dir = new File("E:/");
// create a process and execute notepad.exe and currect environment
Runtime.getRuntime().exec("javac E:/ImageTest.java");
Runtime.getRuntime().exec("java E:/ImageTest > E:/out.txt");
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
我的ImageTest类类似于在运行时获取文件路径的类
public class ImageTest {
private static String DIRECTORY="C:\\Users\\Aashish\\Desktop\\screen";
public static void main(String args[])
{ ImageTest.image(args[0]);
}
public static void image(String FilePath){
try{
//FilePath="h3.jpg";
String FinalFilePath=FilePath.substring(0, FilePath.lastIndexOf('.'));
System.out.println(FinalFilePath);
int IMG_WIDTH200=200,IMG_HEIGHT200=200;
BufferedImage resizeImage200x200Png = resizeImage(FilePath,IMG_WIDTH200,IMG_HEIGHT200);
ImageIO.write(resizeImage200x200Png, "png", new File(DIRECTORY+"\\" + FinalFilePath+ "_"+ String.valueOf(IMG_WIDTH200)+"x"+String.valueOf(IMG_HEIGHT200)+".png"));
int IMG_WIDTH50=50,IMG_HEIGHT50=50;
BufferedImage resizeImage50x50Png = resizeImage(FilePath,IMG_WIDTH50,IMG_HEIGHT50);
ImageIO.write(resizeImage50x50Png, "png", new File(DIRECTORY+"\\" + FinalFilePath+ "_"+ String.valueOf(IMG_WIDTH50)+"x"+String.valueOf(IMG_HEIGHT50)+".png"));
int IMG_WIDTH500=500,IMG_HEIGHT500=500;
BufferedImage resizeImage500x500Png = resizeImage(FilePath,IMG_WIDTH500,IMG_HEIGHT500);
ImageIO.write(resizeImage500x500Png, "png", new File(DIRECTORY+"\\" + FinalFilePath+ "_"+ String.valueOf(IMG_WIDTH500)+"x"+String.valueOf(IMG_HEIGHT500)+".png"));
}catch(IOException e){
System.out.println(e.getMessage());
}
}
private static BufferedImage resizeImage(String FilePath,int IMG_WIDTH,int IMG_HEIGHT ) throws IOException{
String PATH=DIRECTORY+"\\" + FilePath;
System.out.println(PATH);
BufferedImage originalImage = ImageIO.read(new File(PATH));
int type = originalImage.getType() == 0? BufferedImage.TYPE_INT_ARGB : originalImage.getType();
BufferedImage resizedImage = new BufferedImage(IMG_WIDTH, IMG_HEIGHT, type);
Graphics2D g = resizedImage.createGraphics();
g.drawImage(originalImage, 0, 0, IMG_WIDTH, IMG_HEIGHT, null);
g.dispose();
return resizedImage;
}
}
提前感谢。使用类加载器在运行时加载类。然后使用refection调用您的方法;您也可以传递参数 请参阅示例(已测试)代码,您可以将代码放在类似的行中:
package examples;
import java.lang.reflect.Method;
public class Refl {
public static void main(String[] args) throws Exception {
try {
Runtime.getRuntime().exec("javac examples/Child.java");
ClassLoader classLoader = Refl.class.getClassLoader();
Class<?> aClass = classLoader.loadClass("examples.Child");
Method method = aClass.getMethod("Add", Integer.class,
Integer.class);
Object returnValue = method.invoke(aClass.newInstance(), 1, 2);
System.out.println(returnValue);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
}
package examples;
public class Child {
public Integer Add(Integer a, Integer b) {
return a + b;
}
}
包示例;
导入java.lang.reflect.Method;
公共类Refl{
公共静态void main(字符串[]args)引发异常{
试一试{
Runtime.getRuntime().exec(“javac examples/Child.java”);
ClassLoader ClassLoader=Refl.class.getClassLoader();
类aClass=classLoader.loadClass(“examples.Child”);
Method=aClass.getMethod(“Add”,Integer.class,
整数类);
Object returnValue=method.invoke(aClass.newInstance(),1,2);
系统输出打印项次(返回值);
}catch(classnotfounde异常){
e、 printStackTrace();
}
}
}
包装示例;
公营儿童{
公共整数加法(整数a、整数b){
返回a+b;
}
}
使用的命令:
- projDir>javac示例\Refl.java
- projDir>设置类路径=李>
- projDir>java examples.Refl
- projDir>3
ProcessBuilder
开始和上次检查时,重定向不适用于Process
此外,您需要通过ImageTest
要处理的图像的完全限定路径/名称。您应该使用Process#getInputStream
来处理执行的输出,只需在类文件名之后立即传递参数,即Runtime.getRuntime().exec(“java e:/ImageTest\“\”>e:/out.txt”);为什么要使用java来运行命令?这段java代码看起来没有做任何有用的事情,只是妨碍了运行shell命令:从命令行执行所有操作!