使用datax做postgresql到postgresql的数据迁移，报错连接数据库失败

很奇怪的现象是：始终说Reader的数据库是 Available jdbcUrl，然而Writer就会报错：[连接数据库失败. 请检查您的 账号、密码、数据库名称、IP、Port或者向 DBA 寻求帮助(注意网络环境).]. - 具体错误信息为：java.sql.SQLException: No suitable driver found for ["jdbc:postgresql://127.0.0.1:5432/XXXXXX"]。

即使我将配置文件中的writer和reader连接信息互换，依然会报writer连接失败,reader连接正常。

分别将两个数据库作为reader 写到streamwriter 也没有问题 能print出结果

说明两个数据库本身没有问题 配置的连接信息也没有问题 那问题出在哪里呢？？？
-----2017/10/26----
今天又用mysqlwriter测试了，问题依然存在？

配置内容如下
{

"job": {
    "content": [
        {
            "reader": {
                "name": "postgresqlreader", 
                "parameter": {
                    "column": ["name","disp","data"], 
                    "connection": [
                        {
                            "jdbcUrl": ["jdbc:postgresql://139.XXX.XXX.XX:5432/XXXXX"], 
                            "table": ["sys_lic"]
                        }
                    ], 
                    "password": "XXXXXXX", 
                    "username": "XXXXXX"
                }
            }, 
            "writer": {
                "name": "postgresqlwriter", 
                "parameter": {
                    "column": ["name","disp","data"], 
                    "connection": [
                        {
                            "jdbcUrl": ["jdbc:postgresql://127.0.0.1:5432/XXXXXX"], 
                            "table": ["sys_lic"]
                        }
                    ], 
                    "password": "XXXXXX", 
                    "username": "XXXXXXX"
                }
            }
        }
    ], 
    "setting": {
        "speed": {
            "channel": "1"
        }
    }
}

}

报错信息如下
2017-10-25 12:45:15.502 [main] WARN Engine - prioriy set to 0, because NumberFormatException, the value is: null
2017-10-25 12:45:15.505 [main] INFO PerfTrace - PerfTrace traceId=job_-1, isEnable=false, priority=0
2017-10-25 12:45:15.506 [main] INFO JobContainer - DataX jobContainer starts job.
2017-10-25 12:45:15.516 [main] INFO JobContainer - Set jobId = 0
2017-10-25 12:45:16.049 [job-0] INFO OriginalConfPretreatmentUtil - Available jdbcUrl:jdbc:postgresql://139.XXX.XXX.XX:5432/XXXXXX.
2017-10-25 12:45:16.168 [job-0] INFO OriginalConfPretreatmentUtil - table:[sys_lic] has columns:[name,disp,data].
2017-10-25 12:45:16.301 [job-0] ERROR RetryUtil - Exception when calling callable, 异常Msg:Code:[DBUtilErrorCode-10], Description:[连接数据库失败. 请检查您的 账号、密码、数据库名称、IP、Port或者向 DBA 寻求帮助(注意网络环境).]. - 具体错误信息为：java.sql.SQLException: No suitable driver found for ["jdbc:postgresql://127.0.0.1:5432/XXXXXX"]
com.alibaba.datax.common.exception.DataXException: Code:[DBUtilErrorCode-10], Description:[连接数据库失败. 请检查您的 账号、密码、数据库名称、IP、Port或者向 DBA 寻求帮助(注意网络环境).]. - 具体错误信息为：java.sql.SQLException: No suitable driver found for ["jdbc:postgresql://127.0.0.1:5432/XXXXXX"]

at com.alibaba.datax.common.exception.DataXException.asDataXException(DataXException.java:26) ~[datax-common-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.RdbmsException.asConnException(RdbmsException.java:36) ~[plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.DBUtil.connect(DBUtil.java:394) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.DBUtil.connect(DBUtil.java:384) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.DBUtil.access$000(DBUtil.java:22) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.DBUtil$3.call(DBUtil.java:322) ~[plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.DBUtil$3.call(DBUtil.java:319) ~[plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.common.util.RetryUtil$Retry.call(RetryUtil.java:164) ~[datax-common-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.common.util.RetryUtil$Retry.doRetry(RetryUtil.java:111) ~[datax-common-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.common.util.RetryUtil.executeWithRetry(RetryUtil.java:30) [datax-common-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.DBUtil.getConnection(DBUtil.java:319) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.DBUtil.getConnection(DBUtil.java:303) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.util.JdbcConnectionFactory.getConnecttion(JdbcConnectionFactory.java:27) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.writer.util.OriginalConfPretreatmentUtil.dealColumnConf(OriginalConfPretreatmentUtil.java:105) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.writer.util.OriginalConfPretreatmentUtil.dealColumnConf(OriginalConfPretreatmentUtil.java:140) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.writer.util.OriginalConfPretreatmentUtil.doPretreatment(OriginalConfPretreatmentUtil.java:35) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.rdbms.writer.CommonRdbmsWriter$Job.init(CommonRdbmsWriter.java:41) [plugin-rdbms-util-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.plugin.writer.postgresqlwriter.PostgresqlWriter$Job.init(PostgresqlWriter.java:33) [postgresqlwriter-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.core.job.JobContainer.initJobWriter(JobContainer.java:704) [datax-core-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.core.job.JobContainer.init(JobContainer.java:304) [datax-core-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.core.job.JobContainer.start(JobContainer.java:113) [datax-core-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.core.Engine.start(Engine.java:92) [datax-core-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.core.Engine.entry(Engine.java:171) [datax-core-0.0.1-SNAPSHOT.jar:na]
at com.alibaba.datax.core.Engine.main(Engine.java:204) [datax-core-0.0.1-SNAPSHOT.jar:na]