Java调用Geode

Goede序列化

Geode提供了Java序列化之外的序列化选项，为数据存储，传输和语言类型提供更高的性能和更大的灵活性。
Geode DataSerialization 比PDXSerialization快 25％，但使用PDX序列化可以减少反序列化的成本。
Geode 提供的序列化方式（DataSerialization和PDXSerialization），不支持对象的循环引用，如果多次引用相同的对象，则会将每个引用进行序列化，反序列化会生成对象的多个副本。在这种情况下，Java序列化对象一次，当对象进行反序列化时，它将生成具有多个引用的对象的实例。

Java连接Geode示例

依赖JAR：

    <dependency><groupId>org.apache.geode</groupId><artifactId>geode-core</artifactId><version>1.1.0</version></dependency><dependency><groupId>com.gemstone.gemfire</groupId><artifactId>gemfire</artifactId><version>8.2.2</version></dependency><dependency><groupId>org.apache.geode</groupId><artifactId>geode-json</artifactId><version>1.1.0</version></dependency><dependency><groupId>org.apache.geode</groupId><artifactId>geode-common</artifactId><version>1.1.0</version></dependency>

代码示例：

public class UserEntity implements Serializable{private int id;private int age;private String name;private Date registerdDate;//getter and setter...
}public class DataClient {private final static Logger logger  = Logger.getLogger(DataClient.class);Region region = null;@Beforepublic void init(){ClientCache cache = new ClientCacheFactory().addPoolLocator("db", 10334).create();ClientRegionFactory rf = cache.createClientRegionFactory(ClientRegionShortcut.CACHING_PROXY);region = rf.create( "user");}@Testpublic void saveUserEntity(){region.putAll(newUserEntity(10));}@Testpublic void clear(){region.clear();}@Testpublic void delele(){region.remove("");}@Testpublic void update(){Object obj = region.get("108");Map<String, UserEntity> map = new HashMap<String, UserEntity>();UserEntity data= ((UserEntity)obj);data.setAge(12);map.put("108",data);region.putAll(map);}@Testpublic void getUserEntity(){try {Object objList = region.query("select * from /user u where u.age > 10");Object obj = region.get("108");if(objList != null && objList instanceof ResultsBag){Iterator iter = ((ResultsBag) objList).iterator();while(iter.hasNext()){UserEntity UserEntity = (UserEntity) iter.next();System.out.println("UserEntity"+UserEntity);}}if(obj != null && obj instanceof UserEntity){System.out.println("UserEntity"+(UserEntity)obj);}}catch (Exception e){logger.error("error occured.", e);}}@Afterpublic void done(){region.close();}private Map<Integer, UserEntity> newUserEntity(int size){Map<Integer, UserEntity> map = new HashMap<Integer, UserEntity>();for (int i = 0; i < size; i++) {int id = i+100;map.put(id,new UserEntity(id,10+i,"username:"+id,new Date()));}return map;}
}

Geode Query

查询示例

 // Identify your query string.String queryString = "SELECT * FROM /exampleRegion";// Get QueryService from Cache.QueryService queryService = cache.getQueryService();// Create the Query Object.Query query = queryService.newQuery(queryString);// Execute Query locally. Returns results set.SelectResults results = (SelectResults)query.execute();// Find the Size of the ResultSet.int size = results.size();// Iterate through your ResultSet.Portfolio p = (Portfolio)results.iterator().next(); /* Region containing Portfolio object. */

查询语法

WHERE 语法
SELECT * FROM /user WHERE name=‘username’;

LIKE 语法
SELECT * FROM /user WHERE name like ‘use%’;
SELECT * FROM /user WHERE name like ‘_use_’;

添加表别名
SELECT u.id,u.name FROM /user u WHERE u.name=‘username’;

DISTINCT
SELECT DISTINCT u.name FROM /user u

逻辑操作符 AND,OR,NOT
SELECT * FROM /user WHERE id>4 and id<9 and not id = 6

其它比较操作
=,<>,!=,<,⇐,>,>=
IN,NOT IN
SELECT * FROM /user WHERE NOT (ID IN SET(1,2))

LIMIT
SELECT * FROM /user WHERE id>0 LIMIT 10

COUNT
SELECT COUNT(*) FROM /user WHERE ID > 0 LIMIT 50