導言：
如果要對整個數據庫做精確查詢或模糊查詢，我們怎麼纔可以做到？還是通過SQL查詢嗎？答案是否定的。因爲，通過SQL對整個數據庫做精確查詢或模糊查詢，速度將非常的慢；
lucene解決了這個問題。通過對錶或者文本文件預先建立索引，可以很快的實現全文檢索。
思路：
1、通過SQL得到所有表名的集合---->2、遍歷所有的表，分別爲每個表的每個記錄建立索引；同時添加表的中文名以及表的說明的索引---->按Writer\analyzer\document\field的循序建索引。
package com.jrj.datamart.tree;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.Writer;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.apache.lucene.analysis.cn.smart.SmartChineseAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.LockObtainFailedException;
import org.apache.lucene.util.Version;
//import com.jrj.datamart.model.ApiIndicator;
//import com.jrj.datamart.model.ApiInfo;
//import com.jrj.datamart.model.ApiInfoQuery;
//import com.jrj.datamart.service.ApiInfoService;
//對整個數據庫的建立索引；並給每個表添加，表的說明和字段的中文名；方便查詢
//索引 Lucene 3.0.2
public class IndexerDB {
// 保存索引文件的地方
private static String INDEX_DIR = "F:\\MyLuceneDB2\\LuceneFileIndexDir";
private String index_dir;
private File file=new File(INDEX_DIR);
// 將要搜索TXT文件的地方
private String data_dir;
private String DATA_DIR = "F:\\Lucene";
private String entityName;
// private ApiInfo apiInfo;
// private ApiInfoQuery apiInfoQuery = new ApiInfoQuery();
// private ApiInfoService apiInfoService;
// private List<ApiIndicator> apiIndicators = new ArrayList<ApiIndicator>();
// private ApiIndicator apiIndicator;
private StringBuilder newsb = new StringBuilder();
private ResultSet rs = null;
private ResultSet tempRs = null;
private ResultSetMetaData rsmd = null;
// private SmartChineseAnalyzer analyzer = new SmartChineseAnalyzer(
// Version.LUCENE_30, true);
private Document doc;
private String tableName;
public static void main(String[] args) throws Exception {
IndexerDB indexDB=new IndexerDB();
File file=new File(INDEX_DIR);
//1
indexDB.execute(file);
}
//執行對數據庫的索引化
//@param file
//@return
// @throws Exception
//
public String execute(File file) throws Exception {
long start = new Date().getTime();
//2
int numIndexed=getAllTableNameFromDBAndIndexing(file);
long end = new Date().getTime();
System.out.println("Indexing " + numIndexed + " files took "
+ (end - start) + " milliseconds");
return "success";
}
// 查詢所有的表，並遍歷所有的表；
//調用getDataFromTable(tableName)獲取表的記錄；
//調用indexData(writer, rs, tableName)對單張表做索引
public int getAllTableNameFromDBAndIndexing(File file)throws Exception {
ResultSet rs=null;
String sql1 = null;
String sql2 = null;
sql1 = "select [name] from [sysobjects] where [type] = 'u' order by [name]";
sql2 = "show tables";
SmartChineseAnalyzer analyzer = new SmartChineseAnalyzer(
Version.LUCENE_30, true);
IndexWriter writer = new IndexWriter(FSDirectory.open(file),
analyzer, true, IndexWriter.MaxFieldLength.LIMITED);
try {
rs = JDBCUtil.execute(sql1);
} catch (Exception e) {
rs = JDBCUtil.execute(sql2);
}
while (rs.next()) {
tableName=rs.getString(1);
System.out.println("tableName: "+rs.getString(1));
//ResultSetMetaData rsmd = rs.getMetaData();
ResultSet tempRs=getDataFromTable(tableName);
System.out.println("already get data of table");
indexData(writer, tempRs, tableName);
}
int numIndexed = writer.numDocs();
writer.optimize();
writer.close();
return numIndexed;
}
// 取得表的數據
public ResultSet getDataFromTable(String tableName) throws Exception {
String sql = "select * from " + tableName;
System.out.println(""+sql);
//String sql = "select * from " + "HK_STKCODE";
return JDBCUtil.execute(sql);
}
//對特定表的記錄，採用特定writer，索引
//該方法是lucene的indexer的關鍵方法
//writer---->document---->field
private void indexData(IndexWriter writer, ResultSet rs, String tableName)
throws Exception{
if (rs == null) {
return;
}
// 取得實體名
//System.out.println("tableName: " + tableName);
entityName = getEntityName(tableName);
System.out.println(" .entityName: " + entityName);
while (rs.next()) {
doc = new Document();
rsmd = rs.getMetaData();
int colsNum = rsmd.getColumnCount();
//System.out.println("colsNum: "+colsNum);
for (int i = 1; i < colsNum + 1; i++) {
String columnName=rsmd.getColumnName(i);
//System.out.println("columnName: "+columnName);
//System.out.println(" rs.getString(i): "+ rs.getString(i));
// 1、對該條記錄的第一個字段進行索引
doc.add(new Field(columnName, (rs.getString(i)==null?"":rs.getString(i)),
Field.Store.YES, Field.Index.ANALYZED));
}
// 2、在此處添加，表的說明(description);來至於apiinfo;根據表對應的實體名，找到表對應的apiinfo實體
// apiInfoQuery.setEntityname(entityName);
// apiInfo = apiInfoService.gainApiInfoByEntityName(entityName);
// if (apiInfo != null) {
// doc.add(new Field("apiDesc", apiInfo.toString(), Field.Store.YES,
// Field.Index.ANALYZED));
// }
// 3、在此處添加，表的中英文字段：
// 來自於apiindicator;根據表對應的實體名，去APIINFO中取找apiid,再去apiindicator中找apiindicator的實體
// List<ApiIndicator> apiIndicators = apiInfoService
// .gainApiIndicatorsByApiId(apiInfo.getId());
// // 輸出指標和描述結合爲字符串
// for (int i = 0; i < apiIndicators.size(); i++) {
// apiIndicator = apiIndicators.get(i);
// newsb.append(apiIndicator.getCnname() + " ")
// .append(apiIndicator.getEnname() + " ")
// .append(apiIndicator.getDescription() + "");
// newsb.append("\n");
// }
// System.out.println("newsb.toString(): " + newsb.toString());
// doc.add(new Field("outputFields", newsb.toString(),
// Field.Store.YES, Field.Index.ANALYZED));
// 4、文件名
doc.add(new Field("apiName", entityName,
Field.Store.YES, Field.Index.ANALYZED));
writer.addDocument(doc);
}
}
//將表名通過字符串處理成爲實體名
public String getEntityName(String tableName) {
// tableName = tableName.substring(0, tableName.indexOf(".txt"));
StringBuilder sb = new StringBuilder();
// 將"_"替換掉，如果有的話，以便處理成與API對應的實體一樣的字符串。如：PUB_SEITGC.txt，RSH_RSHRPT_INDFO.txt
if (tableName.indexOf("_") != -1) {
String[] subStrings = tableName.split("_");
for (int i = 0; i < subStrings.length; i++) {
sb.append(subStrings[i]);
}
return sb.toString();
} else {
return tableName;
}
}
public String getIndex_dir() {
return index_dir;
}
public void setIndex_dir(String index_dir) {
this.index_dir = index_dir;
}
public String getData_dir() {
return data_dir;
}
public void setData_dir(String data_dir) {
this.data_dir = data_dir;
}
// public ApiInfoService getApiInfoService() {
// return apiInfoService;
// }
//
// public void setApiInfoService(ApiInfoService apiInfoService) {
// this.apiInfoService = apiInfoService;
// }
}
// 數據庫查詢類
//JDBCUtil用於取得連接；JDBCUtil.execute(sql)用於執行SQL，並返回resultset.
package com.jrj.datamart.tree;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JDBCUtil {
public static Connection conn = null;
// 建立連接
static void getConntion() {
try {
String driver_class = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
// ?useUnicode=true&characterEncoding=utf-8
String connection_url = "jdbc:sqlserver://localhost:1433;DatabaseName=UDM";
String user_name = "sa";
String db_password = "sa";
Class.forName(driver_class);
conn = DriverManager.getConnection(connection_url, user_name,
db_password);
conn.setAutoCommit(false);
} catch (Exception e) {
e.printStackTrace();
}
}
// 查詢後，得到數據
public static ResultSet execute(String sql) throws Exception {
// 取得連接
getConntion();
// 寫SQL
// 得到一個statment對象
Statement stmt = conn.createStatement();
// 得到一個結果集
return stmt.executeQuery(sql);
}
static void close() {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static Connection getConn() {
return conn;
}
public static void setConn(Connection conn) {
JDBCWriteExcel.conn = conn;
}
}