Caches

.gitignore

@@ -1,4 +1,5 @@
 target/
+logs/
 pom.xml.tag
 pom.xml.releaseBackup
 pom.xml.versionsBackup

.myeclipse/profiler/MyTimer.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
+<properties>
+<entry key="profiler.settings.instrument.empty.methods">true</entry>
+<entry key="ProfilerCPUSettings_profile_runnables">true</entry>
+<entry key="profiler.settings.n.profiled.threads.limit">32</entry>
+<entry key="ProfilerCPUSettings_filter_type">2</entry>
+<entry key="profiler.settings.obj.alloc.stack.sampling.depth">-1</entry>
+<entry key="profiler.settings.instrument.method.invoke">true</entry>
+<entry key="profiler.settings.instr.scheme">1</entry>
+<entry key="ProfilerMemorySettings_track_every">10</entry>
+<entry key="ProfilerMemorySettings_mode">4</entry>
+<entry key="ProfilerCPUSettings_root_classes">com.xjj.**
+</entry>
+<entry key="ProfilerCPUSettings_filter_value">com.xjj.*</entry>
+<entry key="profiler.settings.istrument.getter.setter.methods">true</entry>
+<entry key="myeclipse.profiling.mode">0</entry>
+<entry key="ProfilerMemorySettings_stacktraces">-1</entry>
+<entry key="profiler.settings.sampling.interval">10</entry>
+<entry key="profiler.settings.cpu.profiling.type">0</entry>
+</properties>

.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,6 @@
+eclipse.preferences.version=1
+encoding//src/main/resources/db.properties=UTF-8
+encoding//src/main/resources/log4j2.xml=UTF-8
+encoding//src/main/resources/profile/development.properties=UTF-8
+encoding//src/main/resources/profile/production.properties=UTF-8
+encoding//src/main/resources/redis.properties=UTF-8

.settings/org.eclipse.wst.common.project.facet.core.xml

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <faceted-project>
   <fixed facet="wst.jsdt.web"/>
-  <installed facet="jst.web" version="2.3"/>
   <installed facet="maven" version="1.0"/>
   <installed facet="wst.jsdt.web" version="1.0"/>
   <installed facet="java" version="1.7"/>
+  <installed facet="jst.web" version="3.0"/>
 </faceted-project>

README.md

@@ -8,10 +8,13 @@ And some customized utilities, encapsulated open-source code.
 另外还有一些小工具、以及对开源代码的二次封装。
 
 Java:
+- Cache: A local cache example using spring cache support
 - FreeMarker: A simple implementation of freeMarker
 - FTP: A simple FTP client with progress shown
+- Guava Cache: example for using Guava cache framework
 - HTTP
 - POI/Excel example
+- Redis: A simple example using spring data redis
 - Spring Batch
 - SpringMVC example
 - Timers

pom.xml

@@ -15,7 +15,13 @@
 			<version>4.12</version>
 			<scope>test</scope>
 		</dependency>
-
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-test</artifactId>
+			<version>4.1.6.RELEASE</version>
+			<scope>test</scope>
+		</dependency>
+
 		<dependency>
 			<groupId>org.freemarker</groupId>
 			<artifactId>freemarker</artifactId>
@@ -46,17 +52,17 @@
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-core</artifactId>
-			<version>2.2.3</version>
+			<version>2.5.3</version>
 		</dependency>
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-databind</artifactId>
-			<version>2.2.3</version>
+			<version>2.5.3</version>
 		</dependency>
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-annotations</artifactId>
-			<version>2.2.3</version>
+			<version>2.5.3</version>
 		</dependency>		
 
 		<dependency>
@@ -70,6 +76,17 @@
 			<version>4.1.6.RELEASE</version>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-redis</artifactId>
+			<version>1.5.0.RELEASE</version>
+		</dependency>
+		<dependency>
+			<groupId>redis.clients</groupId>
+			<artifactId>jedis</artifactId>
+			<version>2.7.2</version>
+		</dependency>
+
 		<!-- FTP -->
 		<dependency>
 			<groupId>commons-net</groupId>
@@ -115,12 +132,49 @@
 			<artifactId>slf4j-api</artifactId>
 			<version>1.7.12</version>
 		</dependency>
+
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+			<version>18.0</version>
+		</dependency>
+
 	</dependencies>
 
-
+	<!-- 选择不同的属性为resource中的变量赋值 -->
+	<profiles>
+		<profile>
+			<id>development</id>
+			<activation>
+				<activeByDefault>true</activeByDefault>
+			</activation>
+			<build>
+				<filters>
+					<filter>src/main/resources/profile/development.properties</filter>
+				</filters>
+			</build>
+		</profile>
+		<profile>
+			<id>production</id>
+			<build>
+				<filters>
+					<filter>src/main/resources/profile/production.properties</filter>
+				</filters>
+			</build>
+		</profile>
+	</profiles>
+
 	<build>
 		<finalName>MyJavaStudio</finalName>
 
+		<!-- 启用filtering功能为resources中的变量赋值 -->
+		<resources>
+			<resource>
+				<directory>src/main/resources</directory>
+				<filtering>true</filtering>
+			</resource>
+		</resources>
+
 		<plugins>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>

src/main/java/com/xjj/cache/guava/MyAbstractCallableCache.java

@@ -0,0 +1,73 @@
+package com.xjj.cache.guava;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+
+/**
+ * 抽象缓存类、缓存模板。
+ * 子类需要实现fetchOrCalculateData从数据库或其他数据源中获取数据。
+ * 
+ * @author XuJijun
+ *
+ * @param <K>
+ * @param <V>
+ * @param <T>
+ */
+public abstract class MyAbstractCallableCache<K, V, T> {
+	private int maximumSize = 1000;					//最大缓存条数
+	private int refreshAfterWriteDuration = 10;		//刷新数据时间
+	private TimeUnit timeUnit = TimeUnit.SECONDS;	//缺省时间单位（秒）
+
+	// 创建缓存
+	public Cache<K, V> cache;/* = CacheBuilder.newBuilder()
+			// 缓存数据的条目
+			.maximumSize(MAXIMUM_SIZE)
+			// 根据键值对被创建或值被替换后多少时间后移除
+			.expireAfterWrite(REFRESH_AFTER_WRITE_IN_SECONDS, TimeUnit.SECONDS)
+			.build();*/
+
+	public MyAbstractCallableCache() {
+		cache = CacheBuilder.newBuilder().maximumSize(maximumSize) 		//缓存数据的最大条目
+				.expireAfterWrite(refreshAfterWriteDuration, timeUnit)	//记录被创建或值被更新多少时间后被移除
+				.build();
+	}
+
+	public MyAbstractCallableCache(int maximumSize,	int refreshAfterWriteDuration, TimeUnit timeUnit) {
+		this.maximumSize = maximumSize;
+		this.refreshAfterWriteDuration = refreshAfterWriteDuration;
+		this.timeUnit = timeUnit;
+		cache = CacheBuilder.newBuilder().maximumSize(maximumSize) 		//缓存数据的最大条目
+				.expireAfterWrite(refreshAfterWriteDuration, timeUnit)	//记录被创建或值被更新多少时间后被移除
+				.build();
+	}
+
+
+
+	public V getCacheData(final K key, final T t){  
+        try {  
+            return cache.get(key, new Callable<V>() {  
+
+                public V call() throws Exception {  
+                    //执行缓存数据方法  
+                    return fetchOrCalculateData(key, t);  
+                }  
+            });  
+        } catch (ExecutionException e) {  
+            e.printStackTrace();  
+            return null;  
+        }  
+    } 
+
+    /**
+     * 从数据库或其他数据源中获取数据、或计算数据
+     * @author XuJijun
+     * @param key
+     * @param t 可以被用来进行计算的一个额外参数
+     * @return
+     */
+    public abstract V fetchOrCalculateData(K key, T t);  
+}

src/main/java/com/xjj/cache/guava/MyAbstractLoadingCache.java

@@ -0,0 +1,61 @@
+package com.xjj.cache.guava;
+
+import java.util.concurrent.TimeUnit;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import com.google.common.cache.RemovalListener;
+import com.google.common.cache.RemovalNotification;
+
+/**
+ * 抽象缓存类、缓存模板。
+ * 子类需要实现fetchData从数据库或其他数据源中获取数据。
+ * @author Xu
+ *
+ * @param <K> key type
+ * @param <V> value type
+ */
+public abstract class MyAbstractLoadingCache <K, V> {
+	//缺省的初始化参数
+	private static int maximumSize = 100;					//最大缓存条数
+	private static int refreshAfterWriteDuration = 2;	//刷新数据时间
+	private static TimeUnit timeUnit = TimeUnit.SECONDS;	//缺省时间单位（秒）
+
+	LoadingCache<K, V> cache;
+
+	public LoadingCache<K, V> getCache() {
+		return cache;
+	}
+
+	public MyAbstractLoadingCache() {
+		this(maximumSize, refreshAfterWriteDuration, timeUnit);
+	}
+
+	public MyAbstractLoadingCache(int maximumSize, int refreshAfterWriteDuration, TimeUnit timeUnit) {
+		cache = CacheBuilder.newBuilder().maximumSize(maximumSize)			//缓存数据的最大条目
+				//.refreshAfterWrite(refreshAfterWriteDuration, timeUnit)		//记录被创建多少时间后被更新
+				.expireAfterWrite(10, timeUnit)								//记录被创建多少时间后被移除
+				.recordStats()
+				.removalListener(new RemovalListener<K, V>() {
+					@Override
+					public void onRemoval(RemovalNotification<K, V> rn) {
+						System.out.println(rn.getKey() + "被移除");
+
+					}
+				}).build(new CacheLoader<K, V>() {
+					@Override
+					public V load(K key) throws Exception {
+						return fetchData(key);
+					}
+				});
+	}
+
+	/**
+	 * 从数据库或其他数据源中获取一个key-value，并被加载到缓存中。
+	 * @author Xu
+	 * @param key
+	 * @return 连同key一起被加载到缓存中的。 
+	 */
+	protected abstract V fetchData(K key);
+}

src/main/java/com/xjj/cache/guava/MyCallableCache.java

@@ -0,0 +1,37 @@
+package com.xjj.cache.guava;
+
+
+/**
+ * 实现和测试CallableCache
+ * @author Xu
+ *
+ */
+public class MyCallableCache extends MyAbstractCallableCache<String, String, String> {
+	//饿汉式单例模式
+	private static final MyCallableCache cc = new MyCallableCache();
+	private MyCallableCache(){};
+	public static MyCallableCache getInstance(){
+		return cc;
+	}
+
+	@Override
+	public String fetchOrCalculateData(String key, String t) {
+        System.out.println("fetchOrCalculateData method...");  
+
+        //返回缓存数据（模拟从数据库获取数据）
+        return "{key:" + key + ", value:" + key + "'s value, and args: " + t + "}"; 
+	}
+
+
+	public static void main(String[] args) {
+		try {
+			for (int i = 0; i < 15; i++) {
+				String value = getInstance().getCacheData("I am key.", "I am arg.");
+				System.out.println(value);
+				Thread.sleep(2000);
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+	}
+}

src/main/java/com/xjj/cache/guava/MyLoadingCache.java

@@ -0,0 +1,60 @@
+package com.xjj.cache.guava;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * 实现和测试LoadingCache
+ * @author Xu
+ *
+ */
+public class MyLoadingCache extends MyAbstractLoadingCache<String, String> {
+	private static final int MAXIMUM_SIZE = 1000;	//最大缓存条数
+	private static final int REFRESH_AFTER_WRITE_DURAION = 200;	//刷新数据时间
+	private static final TimeUnit TIME_UNIT = TimeUnit.SECONDS;	//时间单位（秒）
+
+	//饿汉式单例模式
+	private static final MyLoadingCache lc = new MyLoadingCache();
+	private MyLoadingCache(){
+		super(MAXIMUM_SIZE, REFRESH_AFTER_WRITE_DURAION, TIME_UNIT);
+	};
+
+	public static MyLoadingCache getInstance(){
+		return lc;
+	}
+
+	@Override
+	protected String fetchData(String key) {
+        System.out.println("fetchData method..."+key);  
+
+        //返回缓存数据（模拟从数据库获取数据）
+        return "{key:"+key+", value:"+key+"'s value}"; 
+	}
+
+	public static void main(String[] args) {
+		//MyLoadingCache lc = new MyLoadingCache();
+
+		try {
+			for (int i = 0; i < 100; i++) {
+				String value = lc.getCache().get("I am a key"+i);
+				System.out.println(value);
+			}
+			Thread.sleep(3000);
+			System.out.println("==========================================");
+			for (int i = 0; i < 101; i++) {
+				String value = lc.getCache().get("I am a key"+i);
+				System.out.println(value);
+				Thread.sleep(500);
+			}
+
+			for (int i = 101; i >= 0; i--) {
+				String value = lc.getCache().get("I am a key"+i);
+				System.out.println(value);
+				Thread.sleep(200);
+			}
+
+			System.out.println("stats: "+lc.getCache().stats());
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+	}
+}