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ClassViewer uses Java reflection to generate a text report of a class's structure and behaviours (http://bit.ly/QzT9ZX)
import java.util.*;
import java.lang.reflect.*;
public class ClassViewer
{
private static final String nl = System.getProperty("line.separator");
public static final String viewClassByName(String name)
throws Exception
{
return viewClass(Class.forName(name));
}
public static final String viewObject(Object obj)
throws Exception
{
return viewClass(obj.getClass());
}
public static String viewClass(Class c)
throws Exception
{
Class p;
Boolean bExtends = true;
if (c == null) {
return "Error: Null Reference";
}
StringBuffer out = new StringBuffer(1024);
out.append(Modifier.toString(c.getModifiers()));
out.append(" class ");
out.append(c.getName());
out.append(nl);
p = c.getSuperclass();
while (bExtends){
try {
out.append(" extends ");
out.append(p.getName());
out.append(nl);
p = p.getSuperclass();
} catch (Exception e){
bExtends = false;
}
}
// out.append(" extends ");
// out.append(c.getSuperclass().getName());
// out.append(nl);
Class interfaces[] = c.getInterfaces();
if (interfaces.length > 0) {
out.append(" implements ");
for (int i=0;i<interfaces.length;i++) {
if (i != 0) {
out.append(", ");
}
out.append(interfaces[i].getName());
}
out.append(nl);
}
out.append('{');
out.append(nl);
out.append(" /*** CONSTRUCTORS ***/");
out.append(nl);
Constructor[] constructors = c.getConstructors();
for (int i=0;i<constructors.length;i++) {
out.append(' ');
out.append(ClassViewer.viewConstructor(constructors[i]));
out.append(nl);
out.append(nl);
}
out.append(nl);
out.append(" /*** METHODS ***/");
out.append(nl);
Method[] methods = c.getMethods();
for (int m=0;m<methods.length;m++) {
out.append(' ');
out.append(ClassViewer.viewMethod(methods[m]));
out.append(nl);
out.append(nl);
}
out.append(nl);
out.append(" /*** FIELDS ***/");
out.append(nl);
Field[] fields = c.getFields();
for (int f=0;f<fields.length;f++) {
out.append(' ');
out.append(Modifier.toString(fields[f].getModifiers()));
out.append(' ');
out.append(fields[f].getType().getName());
out.append(' ');
out.append(fields[f].getName());
out.append(nl);
}
out.append(nl);
out.append('}');
return out.toString();
}
public static String viewMethod(Method m)
{
StringBuffer out = new StringBuffer(128);
out.append(Modifier.toString(m.getModifiers()));
out.append(' ');
out.append(m.getReturnType().getName());
out.append(' ');
out.append(m.getName());
out.append('(');
Class[] params = m.getParameterTypes();
for (int p=0;p<params.length;p++) {
if (p != 0) {
out.append(", ");
}
out.append(params[p].getName());
}
out.append(')');
Class[] exc = m.getExceptionTypes();
if (exc.length > 0) {
out.append(nl);
out.append(" throws ");
for (int e=0;e<exc.length;e++) {
if (e != 0) {
out.append(", ");
}
out.append(exc[e].getName());
}
}
return out.toString();
}
public static String viewConstructor(Constructor c)
{
StringBuffer out = new StringBuffer(128);
out.append(Modifier.toString(c.getModifiers()));
out.append(' ');
out.append(c.getName());
out.append('(');
Class[] params = c.getParameterTypes();
for (int p=0;p<params.length;p++) {
if (p != 0) {
out.append(" ,");
}
out.append(params[p].getName());
}
out.append(')');
return out.toString();
}
public static void main(String args[])
throws Exception
{
Class c = null;
if (args.length == 1) {
c = Class.forName(args[1]);
}
else {
c = Class.forName("ClassViewer");
}
System.out.print(ClassViewer.viewClass(c));
}
}
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