一、引子
在我们开发某些软件的过程中，常常需要对windows系统的一些系统设置做一些修改
- 比如我们开发一个代理软件，希望开启代理的时候把系统的代理修改为代理软件的ip和端口，又或者我们希望自己开发的软件，可以在安装的时候就加入到开机自启动中，这时候就需要通过修改注册表的方式修改系统的设置
- 如想要获取IE代理的IP地址，我们就需要拿到下面的注册表条目信息
\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ProxyServer
二、如何修改注册表
2.1、命令行
windows命令行本身就提供了很多处理注册表的命令，通过REG /?可以查看相关命令的使用方法
有了命令我们自然就可以直接调用执行来处理注册表了，示例代码如下
上述代码运行之后，注册表就多了一条新的记录
2.2、工具jar包
有很多通过JNI的方式实现的修改注册表第三方工具jar包可以使用，比较有名的就是 com.ice.jni.registry，点击链接可以直接下载源码，引用jar包和dll后，就可以通过调用它的工具类操作注册表了
- 不过官网的版本dll还是是32位的，这个年代已经看不到32位的机器了，所以我自己处理了一个，点击下载
引入后，就可通过如下的方式操作注册表了
2.3、反射调用java原生native方法
- 上面两个方法一个使用命令不好获取结果，执行复杂命令时也会比较麻烦
- 另外一个使用JNI的方式处理，需要额外处理dll文件
而这个方式
- 不使用 JNI。
- 不使用任何第三方工具
- 不直接使用 WINDOWS API
- 纯JAVA
当然这个也有一些问题，我们后面再说 我们知道com.ice.jni.registry是自己写了一个dll，在启动的时候在静态代码块中用System.loadLibrary()方法加载了一下dll，而java在1.4提供的WindowsPreferences类中其实本身就实现了一些操作注册表的native方法，如下
不过这些方法都是私有方法没法直接使用，但是通过反射，我们依然可以利用这些方法处理注册表，下面给出工具类的完整代码，以及示例
该方式来源于apache的一个开源项目:https://github.com/apache/npanday/tree/trunk/components/dotnet-registry/src/main/java/npanday/registry
package me.ezerror;
/**
* Pure Java Windows Registry access.
* Modified by petrucio@stackoverflow(828681) to add support for
* reading (and writing but not creating/deleting keys) the 32-bits
* registry view from a 64-bits JVM (KEY_WOW64_32KEY)
* and 64-bits view from a 32-bits JVM (KEY_WOW64_64KEY).
*****************************************************************************/
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import java.util.ArrayList;
import java.util.List;
import java.util.prefs.Preferences;
public class WinRegistry {
public static final int HKEY_CURRENT_USER = 0x80000001;
public static final int HKEY_LOCAL_MACHINE = 0x80000002;
public static final int REG_SUCCESS = 0;
public static final int REG_NOTFOUND = 2;
public static final int REG_ACCESSDENIED = 5;
public static final int KEY_WOW64_32KEY = 0x0200;
public static final int KEY_WOW64_64KEY = 0x0100;
private static final int KEY_ALL_ACCESS = 0xf003f;
private static final int KEY_READ = 0x20019;
private static Preferences userRoot = Preferences.userRoot();
private static Preferences systemRoot = Preferences.systemRoot();
private static Class<? extends Preferences> userClass = userRoot.getClass();
private static Method regOpenKey = null;
private static Method regCloseKey = null;
private static Method regQueryValueEx = null;
private static Method regEnumValue = null;
private static Method regQueryInfoKey = null;
private static Method regEnumKeyEx = null;
private static Method regCreateKeyEx = null;
private static Method regSetValueEx = null;
private static Method regDeleteKey = null;
private static Method regDeleteValue = null;
static {
try {
regOpenKey = userClass.getDeclaredMethod("WindowsRegOpenKey", new Class[] { int.class, byte[].class, int.class });
regOpenKey.setAccessible(true);
regCloseKey = userClass.getDeclaredMethod("WindowsRegCloseKey", new Class[] { int.class });
regCloseKey.setAccessible(true);
regQueryValueEx= userClass.getDeclaredMethod("WindowsRegQueryValueEx",new Class[] { int.class, byte[].class });
regQueryValueEx.setAccessible(true);
regEnumValue = userClass.getDeclaredMethod("WindowsRegEnumValue", new Class[] { int.class, int.class, int.class });
regEnumValue.setAccessible(true);
regQueryInfoKey=userClass.getDeclaredMethod("WindowsRegQueryInfoKey1",new Class[] { int.class });
regQueryInfoKey.setAccessible(true);
regEnumKeyEx = userClass.getDeclaredMethod("WindowsRegEnumKeyEx", new Class[] { int.class, int.class, int.class });
regEnumKeyEx.setAccessible(true);
regCreateKeyEx = userClass.getDeclaredMethod("WindowsRegCreateKeyEx", new Class[] { int.class, byte[].class });
regCreateKeyEx.setAccessible(true);
regSetValueEx = userClass.getDeclaredMethod("WindowsRegSetValueEx", new Class[] { int.class, byte[].class, byte[].class });
regSetValueEx.setAccessible(true);
regDeleteValue = userClass.getDeclaredMethod("WindowsRegDeleteValue", new Class[] { int.class, byte[].class });
regDeleteValue.setAccessible(true);
regDeleteKey = userClass.getDeclaredMethod("WindowsRegDeleteKey", new Class[] { int.class, byte[].class });
regDeleteKey.setAccessible(true);
}
catch (Exception e) {
e.printStackTrace();
}
}
private WinRegistry() { }
/**
* Read a value from key and value name
* @param hkey HKEY_CURRENT_USER/HKEY_LOCAL_MACHINE
* @param key
* @param valueName
* @param wow64 0 for standard registry access (32-bits for 32-bit app, 64-bits for 64-bits app)
* or KEY_WOW64_32KEY to force access to 32-bit registry view,
* or KEY_WOW64_64KEY to force access to 64-bit registry view
* @return the value
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static String readString(int hkey, String key, String valueName, int wow64)
throws IllegalArgumentException, IllegalAccessException,
InvocationTargetException
{
if (hkey == HKEY_LOCAL_MACHINE) {
return readString(systemRoot, hkey, key, valueName, wow64);
}
else if (hkey == HKEY_CURRENT_USER) {
return readString(userRoot, hkey, key, valueName, wow64);
}
else {
throw new IllegalArgumentException("hkey=" + hkey);
}
}
/**
* Read value(s) and value name(s) form given key
* @param hkey HKEY_CURRENT_USER/HKEY_LOCAL_MACHINE
* @param key
* @param wow64 0 for standard registry access (32-bits for 32-bit app, 64-bits for 64-bits app)
* or KEY_WOW64_32KEY to force access to 32-bit registry view,
* or KEY_WOW64_64KEY to force access to 64-bit registry view
* @return the value name(s) plus the value(s)
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static Map<String, String> readStringValues(int hkey, String key, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
if (hkey == HKEY_LOCAL_MACHINE) {
return readStringValues(systemRoot, hkey, key, wow64);
}
else if (hkey == HKEY_CURRENT_USER) {
return readStringValues(userRoot, hkey, key, wow64);
}
else {
throw new IllegalArgumentException("hkey=" + hkey);
}
}
/**
* Read the value name(s) from a given key
* @param hkey HKEY_CURRENT_USER/HKEY_LOCAL_MACHINE
* @param key
* @param wow64 0 for standard registry access (32-bits for 32-bit app, 64-bits for 64-bits app)
* or KEY_WOW64_32KEY to force access to 32-bit registry view,
* or KEY_WOW64_64KEY to force access to 64-bit registry view
* @return the value name(s)
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static List<String> readStringSubKeys(int hkey, String key, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
if (hkey == HKEY_LOCAL_MACHINE) {
return readStringSubKeys(systemRoot, hkey, key, wow64);
}
else if (hkey == HKEY_CURRENT_USER) {
return readStringSubKeys(userRoot, hkey, key, wow64);
}
else {
throw new IllegalArgumentException("hkey=" + hkey);
}
}
/**
* Create a key
* @param hkey HKEY_CURRENT_USER/HKEY_LOCAL_MACHINE
* @param key
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static void createKey(int hkey, String key)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
int [] ret;
if (hkey == HKEY_LOCAL_MACHINE) {
ret = createKey(systemRoot, hkey, key);
regCloseKey.invoke(systemRoot, new Object[] { new Integer(ret[0]) });
}
else if (hkey == HKEY_CURRENT_USER) {
ret = createKey(userRoot, hkey, key);
regCloseKey.invoke(userRoot, new Object[] { new Integer(ret[0]) });
}
else {
throw new IllegalArgumentException("hkey=" + hkey);
}
if (ret[1] != REG_SUCCESS) {
throw new IllegalArgumentException("rc=" + ret[1] + " key=" + key);
}
}
/**
* Write a value in a given key/value name
* @param hkey
* @param key
* @param valueName
* @param value
* @param wow64 0 for standard registry access (32-bits for 32-bit app, 64-bits for 64-bits app)
* or KEY_WOW64_32KEY to force access to 32-bit registry view,
* or KEY_WOW64_64KEY to force access to 64-bit registry view
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static void writeStringValue
(int hkey, String key, String valueName, String value, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
if (hkey == HKEY_LOCAL_MACHINE) {
writeStringValue(systemRoot, hkey, key, valueName, value, wow64);
}
else if (hkey == HKEY_CURRENT_USER) {
writeStringValue(userRoot, hkey, key, valueName, value, wow64);
}
else {
throw new IllegalArgumentException("hkey=" + hkey);
}
}
/**
* Delete a given key
* @param hkey
* @param key
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static void deleteKey(int hkey, String key)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
int rc = -1;
if (hkey == HKEY_LOCAL_MACHINE) {
rc = deleteKey(systemRoot, hkey, key);
}
else if (hkey == HKEY_CURRENT_USER) {
rc = deleteKey(userRoot, hkey, key);
}
if (rc != REG_SUCCESS) {
throw new IllegalArgumentException("rc=" + rc + " key=" + key);
}
}
/**
* delete a value from a given key/value name
* @param hkey
* @param key
* @param value
* @param wow64 0 for standard registry access (32-bits for 32-bit app, 64-bits for 64-bits app)
* or KEY_WOW64_32KEY to force access to 32-bit registry view,
* or KEY_WOW64_64KEY to force access to 64-bit registry view
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static void deleteValue(int hkey, String key, String value, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
int rc = -1;
if (hkey == HKEY_LOCAL_MACHINE) {
rc = deleteValue(systemRoot, hkey, key, value, wow64);
}
else if (hkey == HKEY_CURRENT_USER) {
rc = deleteValue(userRoot, hkey, key, value, wow64);
}
if (rc != REG_SUCCESS) {
throw new IllegalArgumentException("rc=" + rc + " key=" + key + " value=" + value);
}
}
//========================================================================
private static int deleteValue(Preferences root, int hkey, String key, String value, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
int[] handles = (int[]) regOpenKey.invoke(root, new Object[] {
new Integer(hkey), toCstr(key), new Integer(KEY_ALL_ACCESS | wow64)
});
if (handles[1] != REG_SUCCESS) {
return handles[1]; // can be REG_NOTFOUND, REG_ACCESSDENIED
}
int rc =((Integer) regDeleteValue.invoke(root, new Object[] {
new Integer(handles[0]), toCstr(value)
})).intValue();
regCloseKey.invoke(root, new Object[] { new Integer(handles[0]) });
return rc;
}
//========================================================================
private static int deleteKey(Preferences root, int hkey, String key)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
int rc =((Integer) regDeleteKey.invoke(root, new Object[] {
new Integer(hkey), toCstr(key)
})).intValue();
return rc; // can REG_NOTFOUND, REG_ACCESSDENIED, REG_SUCCESS
}
//========================================================================
private static String readString(Preferences root, int hkey, String key, String value, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
int[] handles = (int[]) regOpenKey.invoke(root, new Object[] {
new Integer(hkey), toCstr(key), new Integer(KEY_READ | wow64)
});
if (handles[1] != REG_SUCCESS) {
return null;
}
byte[] valb = (byte[]) regQueryValueEx.invoke(root, new Object[] {
new Integer(handles[0]), toCstr(value)
});
regCloseKey.invoke(root, new Object[] { new Integer(handles[0]) });
return (valb != null ? new String(valb).trim() : null);
}
//========================================================================
private static Map<String,String> readStringValues(Preferences root, int hkey, String key, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
HashMap<String, String> results = new HashMap<String,String>();
int[] handles = (int[]) regOpenKey.invoke(root, new Object[] {
new Integer(hkey), toCstr(key), new Integer(KEY_READ | wow64)
});
if (handles[1] != REG_SUCCESS) {
return null;
}
int[] info = (int[]) regQueryInfoKey.invoke(root, new Object[] {
new Integer(handles[0])
});
int count = info[2]; // count
int maxlen = info[3]; // value length max
for(int index=0; index<count; index++) {
byte[] name = (byte[]) regEnumValue.invoke(root, new Object[] {
new Integer(handles[0]), new Integer(index), new Integer(maxlen + 1)
});
String value = readString(hkey, key, new String(name), wow64);
results.put(new String(name).trim(), value);
}
regCloseKey.invoke(root, new Object[] { new Integer(handles[0]) });
return results;
}
//========================================================================
private static List<String> readStringSubKeys(Preferences root, int hkey, String key, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
List<String> results = new ArrayList<String>();
int[] handles = (int[]) regOpenKey.invoke(root, new Object[] {
new Integer(hkey), toCstr(key), new Integer(KEY_READ | wow64)
});
if (handles[1] != REG_SUCCESS) {
return null;
}
int[] info = (int[]) regQueryInfoKey.invoke(root, new Object[] {
new Integer(handles[0])
});
int count = info[0]; // Fix: info[2] was being used here with wrong results. Suggested by davenpcj, confirmed by Petrucio
int maxlen = info[3]; // value length max
for(int index=0; index<count; index++) {
byte[] name = (byte[]) regEnumKeyEx.invoke(root, new Object[] {
new Integer(handles[0]), new Integer(index), new Integer(maxlen + 1)
});
results.add(new String(name).trim());
}
regCloseKey.invoke(root, new Object[] { new Integer(handles[0]) });
return results;
}
//========================================================================
private static int [] createKey(Preferences root, int hkey, String key)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
return (int[]) regCreateKeyEx.invoke(root, new Object[] {
new Integer(hkey), toCstr(key)
});
}
//========================================================================
private static void writeStringValue(Preferences root, int hkey, String key, String valueName, String value, int wow64)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
int[] handles = (int[]) regOpenKey.invoke(root, new Object[] {
new Integer(hkey), toCstr(key), new Integer(KEY_ALL_ACCESS | wow64)
});
regSetValueEx.invoke(root, new Object[] {
new Integer(handles[0]), toCstr(valueName), toCstr(value)
});
regCloseKey.invoke(root, new Object[] { new Integer(handles[0]) });
}
//========================================================================
// utility
private static byte[] toCstr(String str) {
byte[] result = new byte[str.length() + 1];
for (int i = 0; i < str.length(); i++) {
result[i] = (byte) str.charAt(i);
}
result[str.length()] = 0;
return result;
}
public static void main(String[] args) throws InvocationTargetException, IllegalAccessException {
// test by ezerror
String value = readString(HKEY_CURRENT_USER, "Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings", "ProxyServer", 0);
System.out.println(value);
}
}
这种方式虽然直接避开了windows api以及第三方的工具，但是这个方式并不是稳妥的，一方面这种方式本身存在很多限制，或许你期待的操作根本无法通过这种方式实现，另外如果你的项目如果后续可能升级java版本，也许这块代码直接就失效了，所以最好不要将这段代码放在会持续迭代的项目里