JPA与SQLite的配置

下载SQLite的驱动jar包

JPA persistence.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence 
            http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd ">
	<persistence-unit name="luckynew" transaction-type="RESOURCE_LOCAL">
		<properties>
			<property name="hibernate.dialect" value="<span style="color:#ff0000;">com.want.lucky.sqlitedialect.SQLiteDialect</span>" />
			<property name="hibernate.hbm2ddl.auto" value="update" />
			<property name="hibernate.connection.driver_class" value="org.sqlite.JDBC" />
			<property name="hibernate.connection.url" value="jdbc:sqlite://g:/sqlite/db/luckynew.db" />
			<property name="hibernate.connection.username" value="" />
			<property name="hibernate.connection.password" value="" />
			<property name="hibernate.show_sql" value="true" />
		</properties>
	</persistence-unit>
</persistence>

SQLite的方言实现

package com.want.lucky.sqlitedialect;

import java.sql.Types;

import org.hibernate.Hibernate;
import org.hibernate.dialect.Dialect;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.dialect.function.VarArgsSQLFunction;

public class SQLiteDialect extends Dialect {
	public SQLiteDialect() {
		super();
		registerColumnType(Types.BIT, "integer");
		registerColumnType(Types.TINYINT, "tinyint");
		registerColumnType(Types.SMALLINT, "smallint");
		registerColumnType(Types.INTEGER, "integer");
		registerColumnType(Types.BIGINT, "bigint");
		registerColumnType(Types.FLOAT, "float");
		registerColumnType(Types.REAL, "real");
		registerColumnType(Types.DOUBLE, "double");
		registerColumnType(Types.NUMERIC, "numeric");
		registerColumnType(Types.DECIMAL, "decimal");
		registerColumnType(Types.CHAR, "char");
		registerColumnType(Types.VARCHAR, "varchar");
		registerColumnType(Types.LONGVARCHAR, "longvarchar");
		registerColumnType(Types.DATE, "date");
		registerColumnType(Types.TIME, "time");
		registerColumnType(Types.TIMESTAMP, "timestamp");
		registerColumnType(Types.BINARY, "blob");
		registerColumnType(Types.VARBINARY, "blob");
		registerColumnType(Types.LONGVARBINARY, "blob");
		// registerColumnType(Types.NULL, "null");
		registerColumnType(Types.BLOB, "blob");
		registerColumnType(Types.CLOB, "clob");
		registerColumnType(Types.BOOLEAN, "integer");

		registerFunction("concat", new VarArgsSQLFunction(Hibernate.STRING, "", "||", ""));
		registerFunction("mod", new SQLFunctionTemplate(Hibernate.INTEGER, "?1 % ?2"));
		registerFunction("substr", new StandardSQLFunction("substr", Hibernate.STRING));
		registerFunction("substring", new StandardSQLFunction("substr", Hibernate.STRING));
	}

	public boolean supportsIdentityColumns() {
		return true;
	}

	/*
	 * public boolean supportsInsertSelectIdentity() { return true; // As
	 * specify in NHibernate dialect }
	 */

	public boolean hasDataTypeInIdentityColumn() {
		return false; // As specify in NHibernate dialect
	}

	/*
	 * public String appendIdentitySelectToInsert(String insertString) { return
	 * new StringBuffer(insertString.length()+30). // As specify in NHibernate
	 * dialect append(insertString).
	 * append("; ").append(getIdentitySelectString()). toString(); }
	 */

	public String getIdentityColumnString() {
		// return "integer primary key autoincrement";
		return "integer";
	}

	public String getIdentitySelectString() {
		return "select last_insert_rowid()";
	}

	public boolean supportsLimit() {
		return true;
	}

	public String getLimitString(String query, boolean hasOffset) {
		return new StringBuffer(query.length() + 20).append(query).append(hasOffset ? " limit ? offset ?" : " limit ?").toString();
	}

	public boolean supportsTemporaryTables() {
		return true;
	}

	public String getCreateTemporaryTableString() {
		return "create temporary table if not exists";
	}

	public boolean dropTemporaryTableAfterUse() {
		return false;
	}

	public boolean supportsCurrentTimestampSelection() {
		return true;
	}

	public boolean isCurrentTimestampSelectStringCallable() {
		return false;
	}

	public String getCurrentTimestampSelectString() {
		return "select current_timestamp";
	}

	public boolean supportsUnionAll() {
		return true;
	}

	public boolean hasAlterTable() {
		return false; // As specify in NHibernate dialect
	}

	public boolean dropConstraints() {
		return false;
	}

	public String getAddColumnString() {
		return "add column";
	}

	public String getForUpdateString() {
		return "";
	}

	public boolean supportsOuterJoinForUpdate() {
		return false;
	}

	public String getDropForeignKeyString() {
		throw new UnsupportedOperationException("No drop foreign key syntax supported by SQLiteDialect");
	}

	public String getAddForeignKeyConstraintString(String constraintName, String[] foreignKey, String referencedTable, String[] primaryKey, boolean referencesPrimaryKey) {
		throw new UnsupportedOperationException("No add foreign key syntax supported by SQLiteDialect");
	}

	public String getAddPrimaryKeyConstraintString(String constraintName) {
		throw new UnsupportedOperationException("No add primary key syntax supported by SQLiteDialect");
	}

	public boolean supportsIfExistsBeforeTableName() {
		return true;
	}

	public boolean supportsCascadeDelete() {
		return false;
	}
}

测试

工具类

package com.want.lucky.util;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import org.apache.log4j.Logger;

public class DBUtil {

	private static Logger logger = Logger.getLogger(DBUtil.class);

	private static EntityManagerFactory factory = Persistence.createEntityManagerFactory("luckynew");
	private static EntityManager manager = null;

	public static EntityManagerFactory getEntityManagerFactory() {
		if (factory == null) {
			logger.info("实例化EntityManagerFactory!");
			factory = Persistence.createEntityManagerFactory("luckynew");
		}
		return factory;
	}

	public static EntityManager getEntityManager() {
		if (manager == null || !manager.isOpen()) {
			logger.info("实例化EntityManager!");
			manager = getEntityManagerFactory().createEntityManager();
		}
		return manager;
	}
}

public void save() {
	EntityManager manager = DBUtil.getEntityManager();
	manager.getTransaction().begin();
	Item item = new Item();
	item.setName("derek");
	manager.persist(item);
	manager.getTransaction().commit();
	manager.close();
}


public void select() {
	EntityManager manager = DBUtil.getEntityManager();
	Query query = manager.createQuery("from Item o where o.id = ?");
	query.setParameter(1, 2);
	List<Item> list = query.getResultList();
	for (Item item : list) {
		System.out.println(item.getName());
	}
	manager.close();
}