updates for placeholder

disconf-client/src/main/java/com/baidu/disconf/client/support/DisconfAutowareConfig.java

@@ -19,14 +19,18 @@
  * @version 2014-6-6
  */
 public final class DisconfAutowareConfig {
-
+	
     private DisconfAutowareConfig() {
-
+    	
     }
 
     protected static final Logger LOGGER = LoggerFactory.getLogger(DisconfAutowareConfig.class);
-
-    /**
+
+    private static PlaceholderResolver resolver = new PropertyPlaceholderConfigurerResolver();
+
+    private static PropertyPlaceholderHelper propertyPlaceholderHelper = new PropertyPlaceholderHelper();
+
+	/**
      * 先用TOMCAT模式进行导入配置文件，若找不到，则用项目目录模式进行导入
      */
     private static Properties getProperties(final String propertyFilePath) throws Exception {
@@ -127,7 +131,7 @@ private static void autowareConfig(final Object obj, Properties prop) throws Exc
 
                         String defaultValue = config.defaultValue();
                         value = prop.getProperty(name, defaultValue);
-
+                        value = propertyPlaceholderHelper.parseStringValue(value, resolver);
                         // using disconf as prefix to avoid env confusion
                         if (value.equals(defaultValue) && name != null) {
                             if (name.contains("disconf.")) {

disconf-client/src/main/java/com/baidu/disconf/client/support/PlaceholderResolver.java

@@ -0,0 +1,10 @@
+package com.baidu.disconf.client.support;
+
+public interface PlaceholderResolver {
+
+	String placeholderPrefix = "${";
+
+	String placeholderSuffix = "}";
+
+	String resolvePlaceholder(String placeholderName);
+}

disconf-client/src/main/java/com/baidu/disconf/client/support/PropertyPlaceholderConfigurerResolver.java

@@ -0,0 +1,39 @@
+package com.baidu.disconf.client.support;
+
+import java.util.Properties;
+
+public class PropertyPlaceholderConfigurerResolver implements PlaceholderResolver{
+
+	private Properties props;
+
+	public PropertyPlaceholderConfigurerResolver(){
+		//
+	}
+
+	public PropertyPlaceholderConfigurerResolver(Properties props) {
+		this.props = props;
+	}
+
+	public String resolvePlaceholder(String placeholderName) {
+		String propVal = null;
+		if(this.props != null){
+			propVal = this.props.getProperty(placeholderName);
+		}
+		if(propVal == null){
+			propVal = System.getProperty(placeholderName);
+		}
+		if (propVal == null) {
+			propVal = System.getenv(placeholderName);
+		}
+		return propVal;
+	}
+
+	public Properties getProps() {
+		return props;
+	}
+
+	public void setProps(Properties props) {
+		this.props = props;
+	}
+
+}

disconf-client/src/main/java/com/baidu/disconf/client/support/PropertyPlaceholderHelper.java

@@ -0,0 +1,26 @@
+package com.baidu.disconf.client.support;
+
+public class PropertyPlaceholderHelper {
+
+	public String replacePlaceholders(String value, PlaceholderResolver placeholderResolver) {
+		return parseStringValue(value, placeholderResolver);
+	}
+
+	protected String parseStringValue(String strVal, PlaceholderResolver placeholderResolver) {
+
+		StringBuilder result = new StringBuilder(strVal);
+
+		int startIndex = strVal.indexOf(PlaceholderResolver.placeholderPrefix);
+		if (startIndex != -1) {
+			int endIndex = result.indexOf(PlaceholderResolver.placeholderSuffix);
+			if (endIndex != -1) {
+				String placeholder = result.substring(startIndex + PlaceholderResolver.placeholderPrefix.length(), endIndex);
+				String propVal = placeholderResolver.resolvePlaceholder(placeholder);
+				if (propVal != null) {
+					result.replace(startIndex, endIndex + PlaceholderResolver.placeholderSuffix.length(), propVal);
+				}
+			}
+		}
+		return result.toString();
+	}
+}