ASM是一种Java字节码操纵框架，它允许我们在字节码中直接编辑Java程序，以支持自定义转换，优化和验证。如果想要编辑try-catch块的finally块，我们可以使用ASM Tree API。

以下是一个示例代码片段，在try-catch块的finally块上添加一条打印语句：

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class EditFinallyBlockExample {

    public static void main(String[] args) throws IOException, NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
        // 读取class文件的字节码
        ClassReader cr = new ClassReader("TestClass");
        ClassNode cn = new ClassNode();
        cr.accept(cn, 0);

        // 获取需要编辑的方法
        MethodNode mn = (MethodNode)cn.methods.get(0);

        // 使用ASM Tree API编辑finally块
        InsnList insnList = new InsnList();
        insnList.add(new MethodInsnNode(Opcodes.INVOKESTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;", false));
        insnList.add(new InsnNode(Opcodes.LDC));
        insnList.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/Object;)V", false));
        insnList.add(new InsnNode(Opcodes.ATHROW));
        mn.visitLabel(new Label());
        mn.visitTryCatchBlock(mn.instructions.getFirst(), mn.instructions.getLast(), new Label(), "java/lang/Exception");
        mn.visitLabel(new Label());
        mn.visitTryCatchBlock(mn.instructions.getFirst(),