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1. 介绍

java通过 jni 接口调用dmfldr快速装载接口导数据。

开发环境：CentOS7+DM8(Linux)

2. 准备工作

2.1 java项目引入jar

引入jar com.dameng.floader.jar、 DmJdbcDriver18.jar

我采用的方法是将jar包放到lib目录下.pom文件配置引入路径

    <dependency><groupId>com.dm</groupId><artifactId>DmJdbcDriver18</artifactId><version>18</version><scope>system</scope><systemPath>${project.basedir}/lib/DmJdbcDriver18.jar</systemPath></dependency><dependency><groupId>com.dm</groupId><artifactId>Floader</artifactId><version>1.0</version><scope>system</scope><systemPath>${project.basedir}/lib/com.dameng.floader.jar</systemPath></dependency>

2.2 java项目中引入dll

程序在编译的过程中需要调用DM的一些lib动态链接库文件(运行java项目时需要这些dll)

我采用的方式是在启动类的VM options参数配置DLL的路径

DM调用的dll在达梦安装目录的三个目录里面都需要引入

// 我的dm安装目录是 D:\damba\dm8 ，需要自行修改称自己的目录
-Djava.library.path=D:\damba\dm8\drivers;D:\damba\dm8\drivers\logmnr;D:\damba\dm8\bin -Dfile.encoding=UTF-8

2.3 创建表

-- 创建表
CREATE TABLE "SYSDBA"."TEST"
(
"C1" INT,
"C2" INT,
"C3" DATE) STORAGE(ON "MAIN", CLUSTERBTR) ;
-- 插入数据
INSERT INTO test VALUES(1, 1 , '2021-09-15');
INSERT INTO test VALUES(2, 2 , '2021-09-16');
INSERT INTO test VALUES(3, 3 , '2021-09-17');
INSERT INTO test VALUES(4, null , '2021-09-18');

3. 代码实战

3.1 导出所有数据

需求：导出表的所有数据

3.1.1 linux

新建 import_start.ctl 文件（新建目录： /dm8/ctl/insert_test）

LOAD DATA
INFILE '/dm8/ctl/insert_test/test.txt'
INTO TABLE test
FIELDS '|'

在dm8的安装目录bin目录下运行dmfldr脚本

./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_test/import_start.ctl\' mode=\'out\'

执行成功后会生成test.txt文件

3.1.2 java

package com.dm.demo.jni;
import com.dameng.floader.Instance;
import com.dameng.floader.Properties;import java.io.UnsupportedEncodingException;/*** @author xgt(小光头)* @version 1.0* @date 2021-9-18 11:02*/
public class Import_start {public static void main(String[] args){//System.out.println(System.getProperty("java.library.path"));Instance instance = new Instance();try{//初始化if (instance.allocInstance()){instance.setAttribute(Properties.FLDR_ATTR_SERVER, "192.168.60.137");instance.setAttribute(Properties.FLDR_ATTR_PORT, "5236");instance.setAttribute(Properties.FLDR_ATTR_UID, "SYSDBA");instance.setAttribute(Properties.FLDR_ATTR_PWD, "SYSDBA");instance.initializeInstance(null, null, null, "\"SYSDBA\".\"TEST\"");String attribute = instance.getAttribute(Properties.FLDR_ATTR_DATA_CHAR_SET);String ctl = "OPTIONS\r\n" +"(\r\n" +"mode='out'\r\n" +")\r\n" +"Load\r\n" +"infile 'e:\\fldr_out.txt'\r\n" +"Append\r\n" +"into table \"SYSDBA\".\"TEST\"\r\n" +"FIELDS '|'";//导出的ctrl内容instance.setControl(ctl);}else {try {byte[] bytes = instance.getErrorMsg().getBytes("utf-8");System.out.println(new String(bytes, "utf-8"));} catch (UnsupportedEncodingException e) {e.printStackTrace();}}}catch (Exception e){System.out.println(e);}finally{//释放instance.unitialize();instance.free();}}
}

3.2 导出指定列的数据

需求：导出表的某一些指定列并将显示

3.2.1 linux

新建 import_targe_data.ctl 文件（新建目录： /dm8/ctl/insert_test）

OPTIONS
(
SQL ='select C1 from SYSDBA.TEST'
)
LOAD DATA
INFILE '/dm8/ctl/insert_test/test.txt'
INTO TABLE test
FIELDS '|'
(
C1 TERMINATED BY ' '
)

在dm8的安装目录bin目录下运行dmfldr脚本

./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_test/import_targe_data.ctl\' mode=\'out\'

3.2.2 java

package com.dm.demo.jni;
import com.dameng.floader.Instance;
import com.dameng.floader.Properties;import java.io.UnsupportedEncodingException;/*** @author 高垣* @version 1.0* @date 2021-9-18 11:02*/
public class Import_targe_data {public static void main(String[] args){//System.out.println(System.getProperty("java.library.path"));Instance instance = new Instance();try{//初始化if (instance.allocInstance()){instance.setAttribute(Properties.FLDR_ATTR_SERVER, "192.168.60.137");instance.setAttribute(Properties.FLDR_ATTR_PORT, "5236");instance.setAttribute(Properties.FLDR_ATTR_UID, "SYSDBA");instance.setAttribute(Properties.FLDR_ATTR_PWD, "SYSDBA");instance.initializeInstance(null, null, null, "\"SYSDBA\".\"TEST\"");String attribute = instance.getAttribute(Properties.FLDR_ATTR_DATA_CHAR_SET);String ctl = "OPTIONS\r\n" +"(\r\n" +"mode='out'\r\n" +"SQL='select C1 from SYSDBA.TEST'\r\n" +")\r\n" +"Load\r\n" +"infile 'e:\\fldr_out.txt'\r\n" +"Append\r\n" +"into table \"SYSDBA\".\"TEST\"\r\n" +"FIELDS '|'\n" +" (\n" +" C1 TERMINATED BY ' '\n" +" )";//导出的ctrl内容instance.setControl(ctl);}else {try {byte[] bytes = instance.getErrorMsg().getBytes("utf-8");System.out.println(new String(bytes, "utf-8"));} catch (UnsupportedEncodingException e) {e.printStackTrace();}}}catch (Exception e){System.out.println(e);}finally{//释放instance.unitialize();instance.free();}}
}

3.3 导出指定列并修改NULL值

需求：导出指定表的列并将显示NULL的字段修改为其他值

温馨提示：因为在CTL文件中编写语句，存在双引号冲突的问题，使用函数时采用双单引号形式

3.3.1 linux

新建 import_targe_func_data.ctl 文件（新建目录： /dm8/ctl/insert_test）

OPTIONS
(
SQL ='select c1,IFNULL(c2,''1'') c2 from test'
)
LOAD DATA
INFILE '/dm8/ctl/insert_test/test.txt'
INTO TABLE test
FIELDS '|'
(
C1 TERMINATED BY ' ',
C2 TERMINATED BY ' '
)

在dm8的安装目录bin目录下运行dmfldr脚本

./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_test/import_targe_func_data.ctl\' mode=\'out\' ./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_func/test1/test.ctl\' mode=\'out\' select C1,replace(V1,chr(47),''\'') V1 from test1'

3.3.2 java

package com.dm.demo.jni;
import com.dameng.floader.Instance;
import com.dameng.floader.Properties;import java.io.UnsupportedEncodingException;/*** @author 高垣* @version 1.0* @date 2021-9-18 11:02*/
public class TestFloderImport2 {public static void main(String[] args){Instance instance = new Instance();try{//初始化if (instance.allocInstance()){instance.setAttribute(Properties.FLDR_ATTR_SERVER, "192.168.60.137");instance.setAttribute(Properties.FLDR_ATTR_PORT, "5236");instance.setAttribute(Properties.FLDR_ATTR_UID, "SYSDBA");instance.setAttribute(Properties.FLDR_ATTR_PWD, "SYSDBA");instance.initializeInstance(null, null, null, "\"SYSDBA\".\"TEST\"");String attribute = instance.getAttribute(Properties.FLDR_ATTR_DATA_CHAR_SET);String ctl = "OPTIONS\r\n" +"(\r\n" +"mode='out'\r\n" +"SQL='select c1,IFNULL(c2,''1'') c2 from SYSDBA.TEST'\r\n" +")\r\n" +"Load\r\n" +"infile 'e:\\fldr_out.txt'\r\n" +"Append\r\n" +"into table \"SYSDBA\".\"TEST\"\r\n" +"FIELDS '|'\n" +" (\n" +" C1 TERMINATED BY ' ',\n" +" C2 TERMINATED BY ' '\n" +" )";//导出的ctrl内容instance.setControl(ctl);}else {try {byte[] bytes = instance.getErrorMsg().getBytes("utf-8");System.out.println(new String(bytes, "utf-8"));} catch (UnsupportedEncodingException e) {e.printStackTrace();}}}catch (Exception e){System.out.println(e);}finally{//释放instance.unitialize();instance.free();}}
}

===================================

下面的测试是另外一张表测试附表结构

CREATE TABLE "SYSDBA"."TEST1"
(
"C1" INT,
"V1" VARCHAR(50)) STORAGE(ON "MAIN", CLUSTERBTR) ;insert into "SYSDBA"."TEST1"("C1", "V1") VALUES(1, '11/a');
insert into "SYSDBA"."TEST1"("C1", "V1") VALUES(2, '22/2/2');
insert into "SYSDBA"."TEST1"("C1", "V1") VALUES(3, '33/3//');

3.4 导出数据并使用嵌套函数

OPTIONS
(
SQL ='select C1,replace(V1,chr(47),''\'') V1 from test1'
)
LOAD DATA
INFILE '/dm8/ctl/insert_func/test1/test.txt'
INTO TABLE test1
FIELDS '|'
(
C1 TERMINATED BY ' ',
V1 TERMINATED BY ' '
)

[dmdba@localhost bin]$ ./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_func/test1/test1.ctl\' mode=\'out\'

3.5 导出数据并函数嵌套使用char函数

OPTIONS
(
SQL ='select C1,replace(replace(V1,chr(47),chr(41)),chr(41),chr(39)) V1 from test1'
)
LOAD DATA
INFILE '/dm8/ctl/insert_func/test1/test.txt'
INTO TABLE test1
FIELDS '|'
(
C1 TERMINATED BY ' ',
V1 TERMINATED BY ' '
)

[dmdba@localhost bin]$ ./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_func/test1/test2.ctl\' mode=\'out\'

3.6 导出数据并函数嵌套+拼接

OPTIONS
(
SQL ='select C1,replace(replace(V1,chr(47),chr(41)),chr(41),chr(39)|| chr(42)) V1 from test1'
)
LOAD DATA
INFILE '/dm8/ctl/insert_func/test1/test.txt'
INTO TABLE test1
FIELDS '|'
(
C1 TERMINATED BY ' ',
V1 TERMINATED BY ' '
)

[dmdba@localhost bin]$ ./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_func/test1/test3.ctl\' mode=\'out\'

3.7 导出数据并函数嵌套+替换+拼接

OPTIONS
(
SQL ='select C1,replace(replace(V1,''/'',chr(41)),chr(41),chr(39)|| chr(42)) V1 from test1'
)
LOAD DATA
INFILE '/dm8/ctl/insert_func/test1/test.txt'
INTO TABLE test1
FIELDS '|'
(
C1 TERMINATED BY ' ',
V1 TERMINATED BY ' '
)

[dmdba@localhost bin]$ ./dmfldr userid=SYSDBA/SYSDBA@192.168.60.137:5236 control=\'/dm8/ctl/insert_func/test1/test4.ctl\' mode=\'out\'

4. 常见问题

4.1 指定的列与服务器列不一致

编写的ctl文件中 SQL属性的语句执行后的值与FIELDS属性配置的值不一样导致，修改一下就好

4.2 java.lang.UnsatisfiedLinkError

报错：Exception in thread “main” java.lang.UnsatisfiedLinkError: no dmutl in java.library.path

意思是说：运行项目需要去java.library.path中加载dmutldll然后没找到。我的解决方案是在启动类上配置参数去配置这个DLL所在的文件路径