Oracle海量数据导入MongoDB 采用JAVA反射-Penghao

来源：互联网发布：java常用设计模式详解编辑：程序博客网时间：2024/05/20 11:22

首先人员表数据一共有100W条，前期开始是想先用PL/SQL导出为xml格式，然后在SAX解析xml，后来发现xml超过10W条的时候解析起来会有问题，特别占用CPU资源，后改用java程序直接连oracle和mongo，该表有50多个全大写字段,如果先获取到oracle表的列名和值,再写条件判断 if(列名==类属性){ 新实例赋值}, 要写50多个if代码块.觉得用反射更代码更简洁一点。

PatMaster实体类中的NAME字段

String NAME;public String getNAME() {return NAME;}public void setNAME(String nAME) {NAME = nAME;}

Class<PatMaster> c = PatMaster.class;

PatMaster patMaster = c.newInstance();

Method m1 = c.getDeclaredMethod("set" + column, String.class);
m1.setAccessible(true);
m1.invoke(patMaster, value);

column为oracle获取的字段列，String.class是指改set方法需要传入一个String，那么m1就获取到这个set方法了,如果不是public方法，需要setAccessible(true);然后invoke的时候传入实例和数据库中该字段值即可.

全部代码：直接拷过去就可以用，你改个IP定义个你的实体类就好了, 如果搞不定加我QQ468165108

用到的jar包：ojdbc14.jar，mongo-2.5.3.jar

JAR下载地址：http://pan.baidu.com/s/1kTGNVoj 密码：69fz ,

public void OdbcTOMongo() throws Exception {Mongo mongo = new Mongo("192.168.1.3", 30000);DB db = mongo.getDB("test");db.authenticate("user", "user".toCharArray());DBCollection dbc = db.getCollection("patMasterIndex");//自定义数据字典FieldfUtils fu = new FieldfUtils();HashMap<String, String> map = fu.GetMinField();Class.forName("oracle.jdbc.driver.OracleDriver");String url = "jdbc:oracle:thin:@192.168.1.111:1521:dba";String user = "user";String password = "pwd";Connection conn = DriverManager.getConnection(url, user, password);PreparedStatement ps = conn.prepareStatement("select * from PAT_MASTER_INDEX");ResultSet rs = ps.executeQuery();int num = 0;ResultSetMetaData rsmd = rs.getMetaData();int colCount = rsmd.getColumnCount();while (rs.next()) {//计数器 每导入1W行记录输入num++;if(num%10000==0){System.out.println(num);}Class<PatMaster> c = PatMaster.class;PatMaster patMaster = c.newInstance();BasicDBObject bdo = new BasicDBObject();for (int i = 1; i <= colCount; i++) {String column = rsmd.getColumnName(i);Object object = rs.getObject(i);String value = "";if (object == null) {} else {value = (String) object.toString();}Method m1 = c.getDeclaredMethod("set" + column, String.class);m1.setAccessible(true);m1.invoke(patMaster, value);String minName = map.get(column);bdo.put(minName, value);}dbc.insert(bdo);}rs.close();ps.close();conn.close();}

public class FieldfUtils {

public HashMap<String, String> GetPatMasterMinField() throws Exception{
Properties pro = new Properties();
InputStream in =getClass().getResourceAsStream("PAT_MASTER_Min.properties");
pro.load(in);
HashMap<String, String> mapMaxMin = new HashMap<String, String>();
HashMap<String, String> mapMinMax = new HashMap<String, String>();
Iterator it=pro.entrySet().iterator();
while(it.hasNext()){
Map.Entry entry=(Map.Entry)it.next();
String key = (String) entry.getKey();
String value = (String) entry.getValue();
mapMaxMin.put(key, value);
mapMinMax.put(value,key);
}
return mapMaxMin;
}

}

PAT_MASTER_Min.properties-----------------------------

PATIENT_ID=a1
INP_NO=a2
NAME=a3
NAME_PHONETIC=a4
SEX=a5
DATE_OF_BIRTH=a6
BIRTH_PLACE=a7
CITIZENSHIP=a8

PATIENT_ID=a1
左边是oralce字段右边是Mongdb字段自己定义就行了

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