8个错误，大家帮我找找？

Question

错误：
--------------------Configuration: JDK version 1.3.1_04 <Default>--------------------
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:63: invalid method declaration; return type required
     public BookgetABook(long saleid,javax.servlet.jsp.JspWriter out)
            ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:120: invalid method declaration; return type required
     public decrease(long saleid,int num)
            ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:28: cannot resolve symbol
symbol  : class jspWriter  
location: package jsp
     public  Vector getBook(int category,javax.servlet.jsp.jspWriter out,String keyword)
                                                          ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:63: cannot resolve symbol
symbol  : class JspWriter  
location: package jsp
     public BookgetABook(long saleid,javax.servlet.jsp.JspWriter out)
                                                      ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:90: cannot resolve symbol
symbol  : class JspWriter  
location: package jsp
     public BookDetail getDetail(long bookid,javax.servlet.jsp.JspWriter out)
                                                              ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:82: cannot return a value from method whose result type is void
               return book;
                          ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:128: cannot return a value from method whose result type is void
                         return null;
                                     ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:183: cannot resolve symbol
symbol  : variable bookid  
location: class Db.DbBook
                      stmt.executeUpdate("insert into book_detail values('"+bookid+"','"+author+"','"+publisher+"','"+pagenum+"','"+edition+"','"+intro+"')");
                                                                            ^
8 errorsProcess completed.

Answer 1

public BookgetABook(long saleid,javax.servlet.jsp.JspWriter out)
漏一个空格,当然就认为没有返回类型了.
public Book getABook(long saleid,javax.servlet.jsp.JspWriter out)

Answer 2

1. public BookgetABook() 没有返回类型
2. public decrease() 没有返回类型
3,4,5. 加上import javax.servlet.jsp.*
6,7. 返回值不正确和1，2的错误有关

Answer 3

public decrease(long saleid,int num)
问题一样,还是没有返回类型,如果是不需要返回的,就写
public void decrease(long saleid,int num)
并且把下面出错的 return null删掉.

Answer 4

你的环境里没有JspWrite这个类,去载一个.
两个return的错误由上两个解决了.
最后一个错:在这个方法里bookid没有定义.其他地方都有定义为long的.这里漏了.
 

Answer 5

--------------------Configuration: JDK version 1.3.1_04 <Default>--------------------
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:30: cannot resolve symbol
symbol  : class jspWriter  
location: package jsp
     public  Vector getBook(int category,javax.servlet.jsp.jspWriter out,String keyword)
                                                          ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:65: cannot resolve symbol
symbol  : class JspWriter  
location: package jsp
     public Book getABook(long saleid,javax.servlet.jsp.JspWriter out)
                                                       ^
D:\jboss-3.0.2\server\default\deploy\shop.war\DbBook.java:92: cannot resolve symbol
symbol  : class JspWriter  
location: package jsp
     public BookDetail getDetail(long bookid,javax.servlet.jsp.JspWriter out)
                                                              ^
3 errorsProcess completed.

Answer 6

问题就是没有把JspWrite包进来,这个class应该在javax.servlet.jsp下,看看你机器上有没有.这四个是一起的错.

Answer 7

我也知道啊，应该去哪里看啊，兄弟，我用的是JDK和JBOSS

Answer 8

JBOSS我不懂,但起码你的java程序应该要import javax.servlet.jsp.*;
一般是不会有javax包的,我就是去sun载的.