Spring Aspect Oriented Programming Errata

Right Versions

Before Advice pag 146

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
   

   

   

  
     
        
     

BankAccountAspect pag. 165

package org.springaop.chapter.five.concurrent;

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.apache.log4j.Logger;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springaop.utils.Constants;

@Aspect
public class BankAccountAspect {

    @Pointcut("execution(* org.springaop.chapter.five.concurrent.BankAccount.getBalance())")
    public void safeRead() {}

    @Pointcut("execution(* org.springaop.chapter.five.concurrent.BankAccount.creditOperation(*,*)) ")
    public void stateModificationCredit() {}
    
    @Pointcut("execution(* org.springaop.chapter.five.concurrent.BankAccount.debitOperation(*,*)) ")
    public void stateModificationDebit() {}

    @Pointcut("execution(* org.springaop.chapter.five.concurrent.BankAccount.getId())")
    public void getId() {}

    @Pointcut("execution(* org.springaop.chapter.five.concurrent.BankAccount.getStartDate())")
    public void getStartDate() {}

    @Before("safeRead()")
    public void beforeSafeRead() {
        if (log.isInfoEnabled()) {
            log.info("setReadLock");
        }
        rLock.lock();
    }

    @After("safeRead()")
    public void afterSafeRead() {
        rLock.unlock();
        if (log.isInfoEnabled()) {
            log.info("releaseReadLock");
        }
    }

    @Before("stateModificationCredit() || stateModificationDebit()")
    public void beforeSafeWrite() {
        if (log.isInfoEnabled()) {
            log.info("setWriteLock");
        }
        wLock.lock();
    }

    @After("stateModificationCredit() || stateModificationDebit()")
    public void afterSafeWrite() {
        wLock.unlock();
        if (log.isInfoEnabled()) {
            log.info("releaseWriteLock");
        }
    }

    private final ReadWriteLock lock = new ReentrantReadWriteLock();
    private final Lock rLock = lock.readLock();
    private final Lock wLock = lock.writeLock();
    private Logger log = Logger.getLogger(Constants.LOG_NAME);
}

BankAccount pg. 167

package org.springaop.chapter.five.concurrent;

import java.util.Date;

import org.apache.log4j.Logger;
import org.springaop.utils.Constants;

public class BankAccount {
    
    public BankAccount(){
        this.id = 0;
        this.balance = new Float(0);
        this.startDate = new Date();
    }

    public BankAccount(Integer id) {
        this.id = id;
        this.balance = new Float(0);
        this.startDate = new Date();
    }

    public BankAccount(Integer id, Float balance) {
        this.id = id;
        this.balance = balance;
        this.startDate = new Date();
    }

    public BankAccount(Integer id, Float balance, Date start) {
        this.id = id;
        this.balance = balance;
        this.startDate = start;
    }

    public boolean debitOperation(Float debit, Float balance) {
        if (balance < debit) {
            return false;
        } else {
            setBalance(balance - debit);
            return true;
        }
    }

    public void creditOperation(Float credit, Float balance) {
        setBalance(balance+ credit);
    }


    private void setBalance(Float balance) {
        if (log.isInfoEnabled()) {
            log.info("setBalance");
        }
        this.balance = balance;
    }

    public Float getBalance() {
        if (log.isInfoEnabled()) {
            log.info(balance);
        }
        return balance;
    }

    public Integer getId() {
        return id;
    }

    public Date getStartDate() {
        return (Date) startDate.clone();
    }

    private Float balance;
    private final Integer id;
    private final Date startDate;
    private Logger log = Logger.getLogger(Constants.LOG_NAME);
}