Java连接Geode示例

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;    @Before    public void init(){        ClientCache cache = new ClientCacheFactory().addPoolLocator("db", 10334).create();        ClientRegionFactory rf = cache.createClientRegionFactory(ClientRegionShortcut.CACHING_PROXY);        region = rf.create( "user");    }    @Test    public void saveUserEntity(){        region.putAll(newUserEntity(10));    }    @Test    public void clear(){        region.clear();    }    @Test    public void delele(){        region.remove("");    }    @Test    public 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);    }    @Test    public 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);        }    }    @After    public 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