import android.util.Log;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class ReflectUtils {

    /**
     * 在Application中进行初始化即可
     */
    public static void init() {
        try {
            // java.lang.Class
            Class<?> cls = Class.class;
            Method forNameMethod = cls.getMethod("forName", String.class);
            Method getDeclaredMethodMethod = cls.getMethod("getDeclaredMethod", String.class, Class[].class);
            Method getDeclaredFieldsMethod = cls.getMethod("getDeclaredFields");
            Method getDeclaredFieldMethod = cls.getMethod("getDeclaredField", String.class);

            // dalvik.system.VMRuntime
            // Class VMRuntimeCls = Class.forName("dalvik.system.VMRuntime"); // 这个方式也可以获取到
            Class VMRuntimeCls = (Class) forNameMethod.invoke(null, "dalvik.system.VMRuntime");
            Field[] fields = (Field[]) getDeclaredFieldsMethod.invoke(VMRuntimeCls);
            /// Field[] fields = VMRuntimeCls.getDeclaredFields();// 无法获取
            for (Field field : fields) {
                /// Log.d("ReflectUtils", "init: field = " + field);
            }
            //  private static final VMRuntime THE_ONE = new VMRuntime();
            Field THE_ONEField = (Field) getDeclaredFieldMethod.invoke(VMRuntimeCls, "THE_ONE");
            THE_ONEField.setAccessible(true); // private的需要设置访问权限
            Object VMRuntimeObj = THE_ONEField.get(null);

            // public native void setHiddenApiExemptions(String[] signaturePrefixes);
            Method setHiddenApiExemptionsMethod = (Method) getDeclaredMethodMethod.invoke(VMRuntimeCls, "setHiddenApiExemptions", new Class[]{String[].class});
            setHiddenApiExemptionsMethod.invoke(VMRuntimeObj, new Object[]{new String[]{"L"}});

        } catch (Exception e) {
            Log.e("ReflectUtils", "static initializer: ", e);
        }
    }

}