DataSourceWrapper.java

package com.taobao.tddl.group.jdbc;

import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.DataSource;

import com.taobao.tddl.common.model.DBType;
import com.taobao.tddl.group.config.Weight;

/**
 * 一个线程安全的DataSource包装类 DataSource包装类，因为一个GroupDataSource由多个AtomDataSource组成，
 * 且每个AtomDataSource都有对应的读写权重等信息，所以将每一个AtomDataSource封装起来。---add by mazhidan.pt
 * 
 * @author yangzhu
 * @author linxuan refactor as immutable class; dataSourceIndex extends
 */
public class DataSourceWrapper implements DataSource {

    private final String     dataSourceKey;    // 这个DataSource对应的dbKey
    private final String     weightStr;        // 权重信息字符串
    private final Weight     weight;           // 权重信息
    private final DataSource wrappedDataSource; // 被封装的目标DataSource
    private final DBType     dbType;           // 数据库类型
    private final int        dataSourceIndex;  // DataSourceIndex是指这个DataSource在Group中的位置

    public DataSourceWrapper(String dataSourceKey, String weightStr, DataSource wrappedDataSource, DBType dbType,
                             int dataSourceIndex){
        this.dataSourceKey = dataSourceKey;
        this.weight = new Weight(weightStr);
        this.weightStr = weightStr;
        this.wrappedDataSource = wrappedDataSource;
        this.dbType = dbType;

        this.dataSourceIndex = dataSourceIndex;
    }

    public DataSourceWrapper(String dataSourceKey, String weightStr, DataSource wrappedDataSource, DBType dbType){
        this(dataSourceKey, weightStr, wrappedDataSource, dbType, -1);
    }

    /**
     * 验证此DataSource的路由index信息中，是否包含指定的index--add by mazhidan.pt
     */
    public boolean isMatchDataSourceIndex(int specifiedIndex) {
        if (weight.indexes != null && !weight.indexes.isEmpty()) {
            return weight.indexes.contains(specifiedIndex);
        } else {
            return this.dataSourceIndex == specifiedIndex;
        }
    }

    /**
     * 是否有读权重。r0则放回false
     */
    public boolean hasReadWeight() {
        return weight.r != 0;
    }

    /**
     * 是否有写权重。w0则放回false
     */
    public boolean hasWriteWeight() {
        return weight.w != 0;
    }

    public String toString() {
        return new StringBuilder("DataSourceWrapper{dataSourceKey=").append(dataSourceKey)
            .append(", dataSourceIndex=")
            .append(dataSourceIndex)
            .append(",weight=")
            .append(weight)
            .append("}")
            .toString();
    }

    public String getDataSourceKey() {
        return dataSourceKey;
    }

    public String getWeightStr() {
        return weightStr;
    }

    /*
     * public synchronized void setWeightStr(String weightStr) { if
     * ((this.weightStr == weightStr) || (this.weightStr != null &&
     * this.weightStr.equals(weightStr))) return; this.weight = new
     * Weight(weightStr); this.weightStr = weightStr; }
     */

    public Weight getWeight() {
        return weight;
    }

    /*
     * public int getDataSourceIndex() { return dataSourceIndex; }
     */

    /*
     * public void setDataSourceIndex(int dataSourceIndex) {
     * this.dataSourceIndex = dataSourceIndex; }
     */

    public DBType getDBType() {
        return dbType;
    }

    public DataSource getWrappedDataSource() {
        return wrappedDataSource;
    }

    // 以下是javax.sql.DataSource的API实现
    // //////////////////////////////////////////////////////////////////////////
    public Connection getConnection() throws SQLException {
        return wrappedDataSource.getConnection();
    }

    public Connection getConnection(String username, String password) throws SQLException {
        return wrappedDataSource.getConnection(username, password);
    }

    public PrintWriter getLogWriter() throws SQLException {
        return wrappedDataSource.getLogWriter();
    }

    public int getLoginTimeout() throws SQLException {
        return wrappedDataSource.getLoginTimeout();
    }

    public void setLogWriter(PrintWriter out) throws SQLException {
        wrappedDataSource.setLogWriter(out);
    }

    public void setLoginTimeout(int seconds) throws SQLException {
        wrappedDataSource.setLoginTimeout(seconds);
    }

    public boolean isWrapperFor(Class<?> iface) throws SQLException {
        return this.getClass().isAssignableFrom(iface);
    }

    @SuppressWarnings("unchecked")
    public <T> T unwrap(Class<T> iface) throws SQLException {
        try {
            return (T) this;
        } catch (Exception e) {
            throw new SQLException(e);
        }
    }

    /*
     * //Since: 1.6 //java.sql.Wrapper public boolean isWrapperFor(Class<?>
     * iface) throws SQLException { throw new UnsupportedOperationException(); }
     * public <T> T unwrap(Class<T> iface) throws SQLException { throw new
     * UnsupportedOperationException(); }
     */
}