ASM如何生成Java类

发布时间：2021-11-26 17:36:47 作者：柒染
来源：亿速云阅读：233

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, "

", "()V", null, null);
mv.visitCode ();
mv.visitVarInsn (this.ALOAD, 0);
mv.visitMethodInsn (this.INVOKESPECIAL, "java/lang/Object", "", "()V");
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，欢迎关注亿速云行业资讯频道。

ASM如何生成Java类

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