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// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
package org.objectweb.asm.benchmarks;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
/**
* A "Hello World!" class generator using the ASM library.
*
* @author Eric Bruneton
*/
public class AsmGenerator extends Generator {
@Override
public String getVersion() {
for (int i = 9; i >= 5; --i) {
try {
String version = "ASM" + i;
if (Opcodes.class.getField(version) != null) {
return version;
}
} catch (NoSuchFieldException e) {
continue;
}
}
return "";
}
@Override
public byte[] generateClass() {
ClassWriter classWriter = new ClassWriter(ClassWriter.COMPUTE_MAXS);
classWriter.visit(
Opcodes.V1_1, Opcodes.ACC_PUBLIC, "HelloWorld", null, "java/lang/Object", null);
classWriter.visitSource("HelloWorld.java", null);
MethodVisitor methodVisitor =
classWriter.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
methodVisitor.visitMethodInsn(
Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
methodVisitor.visitInsn(Opcodes.RETURN);
methodVisitor.visitMaxs(0, 0);
methodVisitor.visitEnd();
methodVisitor =
classWriter.visitMethod(
Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC, "main", "([Ljava/lang/String;)V", null, null);
methodVisitor.visitFieldInsn(
Opcodes.GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
methodVisitor.visitLdcInsn("Hello world!");
methodVisitor.visitMethodInsn(
Opcodes.INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
methodVisitor.visitInsn(Opcodes.RETURN);
methodVisitor.visitMaxs(0, 0);
methodVisitor.visitEnd();
return classWriter.toByteArray();
}
}
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