Java FieldInfo.getDescriptor方法代码示例

import scouter.javassist.bytecode.FieldInfo; //导入方法依赖的package包/类
private void atFieldRead(CtField f) throws CompileError {
    FieldInfo finfo = f.getFieldInfo2();
    String type = finfo.getDescriptor();

    int i = 0;
    int dim = 0;
    char c = type.charAt(i);
    while (c == '[') {
        ++dim;
        c = type.charAt(++i);
    }

    arrayDim = dim;
    exprType = MemberResolver.descToType(c);

    if (c == 'L')
        className = type.substring(i + 1, type.indexOf(';', i + 1));
    else
        className = null;
}
 

import scouter.javassist.bytecode.FieldInfo; //导入方法依赖的package包/类
/**
 * Sets exprType, arrayDim, and className.
 *
 * @return true if the field type is long or double. 
 */
private boolean setFieldType(FieldInfo finfo) throws CompileError {
    String type = finfo.getDescriptor();

    int i = 0;
    int dim = 0;
    char c = type.charAt(i);
    while (c == '[') {
        ++dim;
        c = type.charAt(++i);
    }

    arrayDim = dim;
    exprType = MemberResolver.descToType(c);

    if (c == 'L')
        className = type.substring(i + 1, type.indexOf(';', i + 1));
    else
        className = null;

    boolean is2byte = dim == 0 && (c == 'J' || c == 'D');
    return is2byte;
}
 

import scouter.javassist.bytecode.FieldInfo; //导入方法依赖的package包/类
/**
 * Creates a public getter method.  The getter method returns the value
 * of the specified field in the class to which this method is added.
 * The created method is initially not static even if the field is
 * static.  Change the modifiers if the method should be static.
 *
 * @param methodName        the name of the getter
 * @param field             the field accessed.
 */
public static CtMethod getter(String methodName, CtField field)
    throws CannotCompileException
{
    FieldInfo finfo = field.getFieldInfo2();
    String fieldType = finfo.getDescriptor();
    String desc = "()" + fieldType;
    ConstPool cp = finfo.getConstPool();
    MethodInfo minfo = new MethodInfo(cp, methodName, desc);
    minfo.setAccessFlags(AccessFlag.PUBLIC);

    Bytecode code = new Bytecode(cp, 2, 1);
    try {
        String fieldName = finfo.getName();
        if ((finfo.getAccessFlags() & AccessFlag.STATIC) == 0) {
            code.addAload(0);
            code.addGetfield(Bytecode.THIS, fieldName, fieldType);
        }
        else
            code.addGetstatic(Bytecode.THIS, fieldName, fieldType);

        code.addReturn(field.getType());
    }
    catch (NotFoundException e) {
        throw new CannotCompileException(e);
    }

    minfo.setCodeAttribute(code.toCodeAttribute());
    CtClass cc = field.getDeclaringClass();
    // a stack map is not needed.
    return new CtMethod(minfo, cc);
}
 

import scouter.javassist.bytecode.FieldInfo; //导入方法依赖的package包/类
/**
 * Creates a public setter method.  The setter method assigns the
 * value of the first parameter to the specified field
 * in the class to which this method is added.
 * The created method is not static even if the field is
 * static.  You may not change it to be static
 * by <code>setModifiers()</code> in <code>CtBehavior</code>.
 *
 * @param methodName        the name of the setter
 * @param field             the field accessed.
 */
public static CtMethod setter(String methodName, CtField field)
    throws CannotCompileException
{
    FieldInfo finfo = field.getFieldInfo2();
    String fieldType = finfo.getDescriptor();
    String desc = "(" + fieldType + ")V";
    ConstPool cp = finfo.getConstPool();
    MethodInfo minfo = new MethodInfo(cp, methodName, desc);
    minfo.setAccessFlags(AccessFlag.PUBLIC);

    Bytecode code = new Bytecode(cp, 3, 3);
    try {
        String fieldName = finfo.getName();
        if ((finfo.getAccessFlags() & AccessFlag.STATIC) == 0) {
            code.addAload(0);
            code.addLoad(1, field.getType());
            code.addPutfield(Bytecode.THIS, fieldName, fieldType);
        }
        else {
            code.addLoad(1, field.getType());
            code.addPutstatic(Bytecode.THIS, fieldName, fieldType);
        }

        code.addReturn(null);
    }
    catch (NotFoundException e) {
        throw new CannotCompileException(e);
    }

    minfo.setCodeAttribute(code.toCodeAttribute());
    CtClass cc = field.getDeclaringClass();
    // a stack map is not needed.
    return new CtMethod(minfo, cc);
}
 

import scouter.javassist.bytecode.FieldInfo; //导入方法依赖的package包/类
private int addFieldrefInfo(CtField f, FieldInfo finfo) {
    ConstPool cp = bytecode.getConstPool();
    String cname = f.getDeclaringClass().getName();
    int ci = cp.addClassInfo(cname);
    String name = finfo.getName();
    String type = finfo.getDescriptor();
    return cp.addFieldrefInfo(ci, name, type);
}