有没有办法在Windows下使用java.util.Preferences而不使用Registry作为后端？

Question

我想使用java.util.Preferences API,但我不希望我的程序尝试读取或写入Windows注册表.我该怎么做？

Answer 1

我相信您已经使用Java读取了对Windows注册表的读/写,然后您希望在使用java.util.PreferencesAPI 时拥有另一个后端而不是注册表

您可以像Bernhard或Croft那样扩展PreferenceAPI,如本文所述:

由于Preferences API是后端中立的,因此您无需关心数据是存储在文件,数据库表还是特定于平台的存储(如Windows注册表)中.

可以在此处看到通过newPreferences扩展的示例.

IMO比使用其他API更好.

例如,搜索扩展的类java.util.prefs.AbstractPreferences:

• 您可以使用XML文件支持的首选项存储:

de.unika.ipd.grgen.util.MyPreferences

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.prefs.AbstractPreferences;
import java.util.prefs.BackingStoreException;

/**
 * Own implementation of the Java preferences API, that does not use
 * a "OS backing store" but relies on importing and exporting the
 * preferences via xml files.
 * Also, If a preference is got, but was not in the tree, it is entered.
 */
public class MyPreferences extends AbstractPreferences {

    private Map<String, String> prefs = new HashMap<String, String>();
    private Map<String, AbstractPreferences> children = new HashMap<String, AbstractPreferences>();

  public MyPreferences(MyPreferences parent, String name) {
    super(parent, name);
  }

  /**
   * @see java.util.prefs.AbstractPreferences#putSpi(java.lang.String, java.lang.String)
   */
  protected void putSpi(String key, String value) {
    prefs.put(key, value);
  }

• 或者您可以将这些首选项存储在LDAP中:

de.tarent.ldap.prefs.LDAPSystemPreferences

import java.util.prefs.AbstractPreferences;
import java.util.prefs.BackingStoreException;

import javax.naming.NamingException;
import javax.naming.directory.Attributes;

import de.tarent.ldap.LDAPException;
import de.tarent.ldap.LDAPManager;

/**
 * @author kirchner
 * 
 * Preferences im LDAP
 */
public class LDAPSystemPreferences extends AbstractPreferences {
    LDAPManager     ldm         = null;
    Properties      properties  = new Properties();
    //Map für key/value der Preferences
    Map             cache       = new HashMap();
    //Map für timestamp der Preferences
    Map             timestamp   = new HashMap();
    private Boolean deleted     = Boolean.FALSE;

• 或者您可以使用简单的属性文件:

com.adito.boot.PropertyPreferences:

import java.util.prefs.AbstractPreferences;
import java.util.prefs.BackingStoreException;
import java.util.prefs.Preferences;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;


/**
 * A simple implementation for the preferences API. That stores preferences
 * in propery files. We do not have to worry about sharing the preferencese 
 * with other JVM instance so there is no need for any kind of synchronising
 * or locking.
 */
public class PropertyPreferences extends AbstractPreferences {