这期内容当中小编将会给大家带来有关ASM如何生成Java类,文章内容丰富且以专业的角度为大家分析和叙述,阅读完这篇文章希望大家可以有所收获。
public class GeneratorBean implements org.objectweb.asm.Opcodes
{
public byte[] getBeanByName (String beanname, String[][] nameAndDesc)
{
ClassWriter classWriter = new ClassWriter (ClassWriter.COMPUTE_MAXS);
classWriter.visit (this.V1_5, this.ACC_PUBLIC, beanname, null, "java/lang/Object", new String[]
{ "java/io/Serializable" });
classWriter.visitField (this.ACC_FINAL | this.ACC_STATIC | this.ACC_PRIVATE, "serialVersionUID", "J", null,
System.currentTimeMillis ());
MethodVisitor mv = classWriter.visitMethod (this.ACC_PUBLIC, "
mv.visitCode ();
mv.visitVarInsn (this.ALOAD, 0);
mv.visitMethodInsn (this.INVOKESPECIAL, "java/lang/Object", "
mv.visitInsn (this.RETURN);
mv.visitEnd ();
String desc = null;
for (int i = 0; i < nameAndDesc.length; i++)
{
nameAndDesc[i][1] = nameAndDesc[i][1].replace (".", "/");
desc = formatDesc (nameAndDesc[i][1]);
classWriter.visitField (this.ACC_PRIVATE, nameAndDesc[i][0], desc, null, null);
mv = classWriter.visitMethod (this.ACC_PUBLIC, "get" + nameAndDesc[i][0], "()" + desc, null, null);
mv.visitCode ();
mv.visitVarInsn (this.ALOAD, 0);
mv.visitFieldInsn (this.GETFIELD, beanname, nameAndDesc[i][0], nameAndDesc[i][1]);
mv.visitInsn (this.IRETURN);
mv.visitEnd ();
mv = classWriter.visitMethod (this.ACC_PUBLIC, "set" + nameAndDesc[i][0], "(" + desc + ")V", null, null);
mv.visitCode ();
mv.visitVarInsn (ALOAD, 0);
mv.visitVarInsn (ILOAD, 1);
mv.visitFieldInsn (PUTFIELD, beanname, nameAndDesc[i][0], nameAndDesc[i][1]);
mv.visitInsn (RETURN);
mv.visitEnd ();
}
return classWriter.toByteArray ();
}
上述就是小编为大家分享的ASM如何生成Java类了,如果刚好有类似的疑惑,不妨参照上述分析进行理解。如果想知道更多相关知识,欢迎关注编程网行业资讯频道。