所以我试图让这个应用程序从反射中调用android.os.SystemProperties，但它有点疼，所以如果有人可以帮助它将不胜感激。
所以这是代码的一部分让我失望：
String str1 = SystemPropertiesProxy.get("ro.url.changelog");
String str2 = SystemPropertiesProxy.get("ro.build.incremental");
String str4 = String.format("?version=%s", str2);
Object[] arrayOfObject1 = new Object[2];
arrayOfObject1[0] = str1;
arrayOfObject1[1] = str4;
String str5 = String.format("%s%s", arrayOfObject1);
...
myWebView.loadUrl(str5);
上面的代码给出了错误：“Type SystemPropertiesProxy中的方法get（Context，String）不适用于”String str1 = SystemPropertiesProxy.get（“ro.url”中的参数（String）“。更新日志“）” 这是我尝试设置访问android.os.SystemProperties的反射代码：
package com.package.name;
import java.io.File;
import java.lang.reflect.Method;
import android.content.Context;
import dalvik.system.DexFile;
public class SystemPropertiesProxy
{
/**
* This class cannot be instantiated
*/
private SystemPropertiesProxy(){
}
/**
* Get the value for the given key.
* @return an empty string if the key isn't found
* @throws IllegalArgumentException if the key exceeds 32 characters
*/
public static String get(Context context, String key) throws IllegalArgumentException {
String ret= "";
try{
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//Parameters Types
@SuppressWarnings("rawtypes")
Class[] paramTypes= new Class[1];
paramTypes[0]= String.class;
Method get = SystemProperties.getMethod("get", paramTypes);
//Parameters
Object[] params= new Object[1];
params[0]= new String(key);
ret= (String) get.invoke(SystemProperties, params);
}catch( IllegalArgumentException iAE ){
throw iAE;
}catch( Exception e ){
ret= "";
//TODO
}
return ret;
}
/**
* Get the value for the given key.
* @return if the key isn't found, return def if it isn't null, or an empty string otherwise
* @throws IllegalArgumentException if the key exceeds 32 characters
*/
public static String get(Context context, String key, String def) throws IllegalArgumentException {
String ret= def;
try{
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//Parameters Types
@SuppressWarnings("rawtypes")
Class[] paramTypes= new Class[2];
paramTypes[0]= String.class;
paramTypes[1]= String.class;
Method get = SystemProperties.getMethod("get", paramTypes);
//Parameters
Object[] params= new Object[2];
params[0]= new String(key);
params[1]= new String(def);
ret= (String) get.invoke(SystemProperties, params);
}catch( IllegalArgumentException iAE ){
throw iAE;
}catch( Exception e ){
ret= def;
//TODO
}
return ret;
}
/**
* Get the value for the given key, and return as an integer.
* @param key the key to lookup
* @param def a default value to return
* @return the key parsed as an integer, or def if the key isn't found or
* cannot be parsed
* @throws IllegalArgumentException if the key exceeds 32 characters
*/
public static Integer getInt(Context context, String key, int def) throws IllegalArgumentException {
Integer ret= def;
try{
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//Parameters Types
@SuppressWarnings("rawtypes")
Class[] paramTypes= new Class[2];
paramTypes[0]= String.class;
paramTypes[1]= int.class;
Method getInt = SystemProperties.getMethod("getInt", paramTypes);
//Parameters
Object[] params= new Object[2];
params[0]= new String(key);
params[1]= new Integer(def);
ret= (Integer) getInt.invoke(SystemProperties, params);
}catch( IllegalArgumentException iAE ){
throw iAE;
}catch( Exception e ){
ret= def;
//TODO
}
return ret;
}
/**
* Get the value for the given key, and return as a long.
* @param key the key to lookup
* @param def a default value to return
* @return the key parsed as a long, or def if the key isn't found or
* cannot be parsed
* @throws IllegalArgumentException if the key exceeds 32 characters
*/
public static Long getLong(Context context, String key, long def) throws IllegalArgumentException {
Long ret= def;
try{
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties= cl.loadClass("android.os.SystemProperties");
//Parameters Types
@SuppressWarnings("rawtypes")
Class[] paramTypes= new Class[2];
paramTypes[0]= String.class;
paramTypes[1]= long.class;
Method getLong = SystemProperties.getMethod("getLong", paramTypes);
//Parameters
Object[] params= new Object[2];
params[0]= new String(key);
params[1]= new Long(def);
ret= (Long) getLong.invoke(SystemProperties, params);
}catch( IllegalArgumentException iAE ){
throw iAE;
}catch( Exception e ){
ret= def;
//TODO
}
return ret;
}
/**
* Get the value for the given key, returned as a boolean.
* Values 'n', 'no', '0', 'false' or 'off' are considered false.
* Values 'y', 'yes', '1', 'true' or 'on' are considered true.
* (case insensitive).
* If the key does not exist, or has any other value, then the default
* result is returned.
* @param key the key to lookup
* @param def a default value to return
* @return the key parsed as a boolean, or def if the key isn't found or is
* not able to be parsed as a boolean.
* @throws IllegalArgumentException if the key exceeds 32 characters
*/
public static Boolean getBoolean(Context context, String key, boolean def) throws IllegalArgumentException {
Boolean ret= def;
try{
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//Parameters Types
@SuppressWarnings("rawtypes")
Class[] paramTypes= new Class[2];
paramTypes[0]= String.class;
paramTypes[1]= boolean.class;
Method getBoolean = SystemProperties.getMethod("getBoolean", paramTypes);
//Parameters
Object[] params= new Object[2];
params[0]= new String(key);
params[1]= new Boolean(def);
ret= (Boolean) getBoolean.invoke(SystemProperties, params);
}catch( IllegalArgumentException iAE ){
throw iAE;
}catch( Exception e ){
ret= def;
//TODO
}
return ret;
}
/**
* Set the value for the given key.
* @throws IllegalArgumentException if the key exceeds 32 characters
* @throws IllegalArgumentException if the value exceeds 92 characters
*/
public static void set(Context context, String key, String val) throws IllegalArgumentException {
try{
@SuppressWarnings("unused")
DexFile df = new DexFile(new File("/system/app/Settings.apk"));
@SuppressWarnings("unused")
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = Class.forName("android.os.SystemProperties");
//Parameters Types
@SuppressWarnings("rawtypes")
Class[] paramTypes= new Class[2];
paramTypes[0]= String.class;
paramTypes[1]= String.class;
Method set = SystemProperties.getMethod("set", paramTypes);
//Parameters
Object[] params= new Object[2];
params[0]= new String(key);
params[1]= new String(val);
set.invoke(SystemProperties, params);
}
catch( IllegalArgumentException iAE ){
throw iAE;
}
catch( Exception e ){
//TODO
}
}
}
再次感谢任何帮助。感谢。
答案 0 :(得分：1)
你没有写这是编译错误
没有方法
public static String get(String key){}
。使用
public static String get(Context context, String key):
SystemPropertiesProxy.get(context, "ro.url.changelog");
无论如何......使用私有API不是一个好主意