最近在研究BDB时发现速度特别快（非关系型数据库）下面我给大家共享一下我在学习的过程中的一些收获和问题，不知道哪位大神帮忙解决一下。主要在putNoDupData，不知道该怎么使用
代码语言：javascript复制package com.bdb;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.util.ArrayList;
import java.util.List;
import jodd.io.FileUtil;
import com.sleepycat.je.Cursor;
import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseConfig;
import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.Environment;
import com.sleepycat.je.EnvironmentConfig;
import com.sleepycat.je.LockMode;
import com.sleepycat.je.OperationStatus;
public class MyBerkeleyDB {
private Environment env;
private Database db;
public MyBerkeleyDB() {
}
public void setUp(String path, long cacheSize) {
EnvironmentConfig envConfig = new EnvironmentConfig();
envConfig.setAllowCreate(true);
envConfig.setCacheSize(cacheSize);
try {
env = new Environment(new File(path),envConfig);
} catch (DatabaseException e) {
e.printStackTrace();
}
}
public void open(String dbName) {
DatabaseConfig dbConfig = new DatabaseConfig();
dbConfig.setAllowCreate(true);//是否允许创建
dbConfig.setReplicated(false);//是否允许重复
//dbConfig.setSortedDuplicates(true);这里我已经设置了，我不知道下面在我putNoDupData会出现异常
try {
db = env.openDatabase(null, dbName, dbConfig);
} catch (DatabaseException e) {
e.printStackTrace();
}
}
public void close() {
try {
if(db != null) {
db.close();
}
if(env != null) {
env.close();
}
} catch (DatabaseException e) {
e.printStackTrace();
}
}
public String get(String key) throws Exception {
DatabaseEntry queryKey = new DatabaseEntry();
DatabaseEntry value = new DatabaseEntry();
queryKey.setData(key.getBytes("UTF-8"));
OperationStatus status = db.get(null, queryKey, value,
LockMode.DEFAULT);
if (status == OperationStatus.SUCCESS) {
return new String(value.getData());
}
return null;
}
/**
* put data for one to one
* @param key
* @param value
* @return
* @throws Exception
*/
public boolean put(String key, String value) throws Exception {
byte[] theKey = key.getBytes("UTF-8");
byte[] theValue = value.getBytes("UTF-8");
OperationStatus status = db.put(null, new DatabaseEntry(theKey),new DatabaseEntry(theValue));
if(status == OperationStatus.SUCCESS) {
return true;
}
return false;
}
/**
* get all value
*/
public static List<String> readFile(String filePathAndName)throws IOException {
FileInputStream fis = new FileInputStream(filePathAndName);
InputStreamReader isr = new InputStreamReader(fis, "UTF-8");
BufferedReader br = new BufferedReader(isr);
LineNumberReader lnr = new LineNumberReader(br);
List<String> returnValue = new ArrayList<String>();
int cnt = 0;
while (true) {
cnt ;
String tempStr = lnr.readLine();
if (tempStr == null)
break;
/*if(cnt>1)
break;*/
/*if(cnt<=1000000)
continue;
if(cnt>1500000)
break;*/
if (tempStr.length() < 2)
continue;
returnValue.add(tempStr);
}
lnr.close();
br.close();
isr.close();
fis.close();
return returnValue;
}
public List<String> getAllValue(){
List<String> returnValue = new ArrayList<String>();
DatabaseEntry keyEntry = new DatabaseEntry();
DatabaseEntry dataEntry = new DatabaseEntry();
Cursor cursor = db.openCursor(null, null);
while(cursor.getNext(keyEntry, dataEntry, LockMode.DEFAULT) == OperationStatus.SUCCESS){
returnValue.add(new String(dataEntry.getData()));
}
cursor.close();
return returnValue;
}
public int getCount(String key){
DatabaseEntry keyEntry = new DatabaseEntry();
DatabaseEntry dataEntry = new DatabaseEntry();
keyEntry.setData(key.getBytes());
Cursor cursor = db.openCursor(null, null);
cursor.getSearchKey(keyEntry, dataEntry, LockMode.DEFAULT);
int returnValue = 0;
try{
returnValue = cursor.count();
}catch(IllegalStateException e){
returnValue = 0;
}finally{
cursor.close();
close();
}
return returnValue;
}
public static void main(String[] args) throws Exception {
MyBerkeleyDB mbdb = new MyBerkeleyDB();
/*mbdb.get("myKey1");
System.out.println(mbdb.get("myKey1"));*/
mbdb.setUp("D:\bdb", 1000000);//设置文件夹进行存储，并设置大小
mbdb.open("myDB");
//System.out.println(mbdb.get("myKey8"));
//System.out.println(mbdb.getCount("myKey1"));
//System.out.println(mbdb.get("myKeyq3"));
List<String> list1 = mbdb.getAllValue();
for(String str:list1){
System.out.println(str);//从库里取出数据
//FileUtil.appendString("f:\bdb2.txt", str);
}
System.out.println("开始向Berkeley DB中存入数据...");
List<String> listData = readFile("d:/。。.txt");//读取数据
try {
int i = 0;
for(String list:listData){
String key = "myKey" i;
String value = "myValuesq" list;
mbdb.put(key , value);//存入数据
i ;
}
} catch (Exception e) {
e.printStackTrace();
}
mbdb.close();
}}
