Suppose that I have a .class file, can I get all t开发者_StackOverflow中文版he methods included in that class ?
Straight from the source: http://java.sun.com/developer/technicalArticles/ALT/Reflection/ Then I modified it to be self contained, not requiring anything from the command line. ;-)
import java.lang.reflect.*;
/**
Compile with this:
C:\Documents and Settings\glow\My Documents\j>javac DumpMethods.java
Run like this, and results follow
C:\Documents and Settings\glow\My Documents\j>java DumpMethods
public void DumpMethods.foo()
public int DumpMethods.bar()
public java.lang.String DumpMethods.baz()
public static void DumpMethods.main(java.lang.String[])
*/
public class DumpMethods {
public void foo() { }
public int bar() { return 12; }
public String baz() { return ""; }
public static void main(String args[]) {
try {
Class thisClass = DumpMethods.class;
Method[] methods = thisClass.getDeclaredMethods();
for (int i = 0; i < methods.length; i++) {
System.out.println(methods[i].toString());
}
} catch (Throwable e) {
System.err.println(e);
}
}
}
To know about all methods use this statement in console:
javap -cp jar-file.jar packagename.classname
or
javap class-file.class packagename.classname
or for example:
javap java.lang.StringBuffer
You can use the Reflection API
package tPoint;
import java.io.File;
import java.lang.reflect.Method;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
public class ReadClasses {
public static void main(String[] args) {
try {
Class c = Class.forName("tPoint" + ".Sample");
Object obj = c.newInstance();
Document doc =
DocumentBuilderFactory.newInstance().newDocumentBuilder()
.parse(new File("src/datasource.xml"));
Method[] m = c.getDeclaredMethods();
for (Method e : m) {
String mName = e.getName();
if (mName.startsWith("set")) {
System.out.println(mName);
e.invoke(obj, new
String(doc.getElementsByTagName(mName).item(0).getTextContent()));
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
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