set Value Of Field - Android java.lang.reflect

Android examples for java.lang.reflect:Field Value

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Description

set Value Of Field

Demo Code


//package com.java2s;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import java.util.WeakHashMap;
import android.text.TextUtils;
import android.util.Log;

public class Main {
    private static final WeakHashMap<Field, Method> setterCache = new WeakHashMap<Field, Method>();

    public static void setValueOfField(Object object, String fieldName,
            Object value) {//from  w w  w. ja  v  a 2s.  co m
        if (object == null) {
            return;
        }
        Class<?> clazz = object.getClass();
        try {
            final Field field = clazz.getDeclaredField(fieldName);
            Method setter = getSetter(field);
            if (setter != null) {
                Class<?> paramType = setter.getParameterTypes()[0];

                if (value == null) {
                    value = getBasicTypeNullValue(paramType);
                }

                setter.invoke(object, value);
                return;
            }

            field.setAccessible(true);
            if (value == null) {
                value = getBasicTypeNullValue(object.getClass());
            }

            field.set(object, value);
        } catch (NoSuchFieldException e) {
            Log.e("ReflectUtil File", "setValueOfField:"
                    + object.getClass().getName() + "#" + fieldName);
            throw new IllegalArgumentException(e);
        } catch (IllegalAccessException e) {
            Log.e("ReflectUtil File", "setValueOfField:"
                    + object.getClass().getName() + "#" + fieldName);
            throw new IllegalArgumentException(e);
        } catch (InvocationTargetException e) {
            Log.e("ReflectUtil File", "setValueOfField:"
                    + object.getClass().getName() + "#" + fieldName);
            throw new IllegalArgumentException(e);
        } catch (IllegalArgumentException e) {
            Log.e("ReflectUtil File", "setValueOfField:"
                    + object.getClass().getName() + "#" + fieldName + "|"
                    + value);
            throw new IllegalArgumentException(e);
        }
    }

    public static Field getDeclaredField(Object object, String fieldName) {
        Field field = null;

        Class<?> clazz = object.getClass();

        while (clazz != Object.class) {
            try {
                field = clazz.getDeclaredField(fieldName);
                return field;
            } catch (Exception e) {
                Log.i("ReflectUtil File", "");

                clazz = clazz.getSuperclass();
            }

        }

        return null;
    }

    public static Method getSetter(Field field) {
        String fieldName = field.getName();
        Method setter = (Method) setterCache.get(field);
        if (setter != null) {
            return setter;
        }
        String methodName = generateSetterName(fieldName);
        Class<?> clazz = field.getDeclaringClass();
        try {
            setter = clazz.getMethod(methodName,
                    new Class[] { field.getType() });
            setterCache.put(field, setter);
            return setter;
        } catch (SecurityException e) {
            return null;
        } catch (NoSuchMethodException e) {
        }
        return null;
    }

    public static Object getBasicTypeNullValue(Class<?> clazz) {
        if (clazz == Integer.TYPE) {
            return Integer.valueOf(0);
        }
        if (clazz == Long.TYPE) {
            return Long.valueOf(0L);
        }
        if (clazz == Float.TYPE) {
            return Float.valueOf(0.0F);
        }
        if (clazz == Double.TYPE) {
            return Double.valueOf(0.0D);
        }
        if (clazz == Byte.TYPE) {
            return Byte.valueOf((byte) 0);
        }
        if (clazz == Short.TYPE) {
            return Short.valueOf((short) 0);
        }
        if (clazz == Character.TYPE) {
            return 0;
        }
        if (clazz == Boolean.TYPE) {
            return Boolean.FALSE;
        }

        return null;
    }

    public static String generateSetterName(String fieldName) {
        if (TextUtils.isEmpty(fieldName)) {
            throw new IllegalArgumentException("invalid field.");
        }
        String firstCH = fieldName.substring(0);
        Character secondCH = null;
        if (fieldName.length() > 1) {
            secondCH = Character.valueOf(fieldName.charAt(1));
        }
        String setterName = null;
        if ((secondCH == null)
                || (!Character.isUpperCase(secondCH.charValue()))) {
            setterName = "set"
                    + fieldName
                            .replaceFirst(firstCH, firstCH.toUpperCase());
        } else {
            setterName = "set" + fieldName;
        }
        return setterName;
    }
}

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