密码生成器

这个是工具类   可以拿来直接使用哦！！！！

/*
* Copyright 2002-2011 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.security.crypto.bcrypt;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.security.crypto.password.PasswordEncoder;

import java.security.SecureRandom;
import java.util.regex.Pattern;

/**
* Implementation of PasswordEncoder that uses the BCrypt strong hashing function. Clients
* can optionally supply a "strength" (a.k.a. log rounds in BCrypt) and a SecureRandom
* instance. The larger the strength parameter the more work will have to be done
* (exponentially) to hash the passwords. The default value is 10.
*
* @author Dave Syer
*
*/
public class BCryptPasswordEncoder implements PasswordEncoder {
private Pattern BCRYPT_PATTERN = Pattern
.compile("\A\$2a?\$\d\d\$[./0-9A-Za-z]{53}");
private final Log logger = LogFactory.getLog(getClass());

private final int strength;

private final SecureRandom random;

public BCryptPasswordEncoder() {
this(-1);
}

/**
* @param strength the log rounds to use, between 4 and 31
*/
public BCryptPasswordEncoder(int strength) {
this(strength, null);
}

/**
* @param strength the log rounds to use, between 4 and 31
* @param random the secure random instance to use
*
*/
public BCryptPasswordEncoder(int strength, SecureRandom random) {
if (strength != -1 && (strength < BCrypt.MIN_LOG_ROUNDS || strength > BCrypt.MAX_LOG_ROUNDS)) {
throw new IllegalArgumentException("Bad strength");
}
this.strength = strength;
this.random = random;
}

public String encode(CharSequence rawPassword) {
String salt;
if (strength > 0) {
if (random != null) {
salt = BCrypt.gensalt(strength, random);
}
else {
salt = BCrypt.gensalt(strength);
}
}
else {
salt = BCrypt.gensalt();
}
return BCrypt.hashpw(rawPassword.toString(), salt);
}

public boolean matches(CharSequence rawPassword, String encodedPassword) {
if (encodedPassword == null || encodedPassword.length() == 0) {
logger.warn("Empty encoded password");
return false;
}

if (!BCRYPT_PATTERN.matcher(encodedPassword).matches()) {
logger.warn("Encoded password does not look like BCrypt");
return false;
}

return BCrypt.checkpw(rawPassword.toString(), encodedPassword);
}
}

用的时候这样去取就很OK哦！！！！

 user.setPassword(passwordEncoder.encode(password));