在jsp

Question

我想通过使用servlet

将会话bean内的对象显示在jsp中

这是我的servlet

  <form action="profile" method="POST">

       <input  id="User Name" type="text" value="${user.username } " name="userName" /><br>
       <input id="Password" type="text" placeholder="Password"  name="password" value="${user.password}" size="20" /><br>         
       <input id="Name" type="text" placeholder="Name"  name="Name" value="${user.userInfo}" /><br>


    </form>
    </div>
</body>

userInfo是一个包含名称的对象.....所以我将如何在userInfo中显示对象....... $ {user.userInfo}的结果只返回数据库引用哪个是Database.UserInformation [id = 401]我将如何访问id内的项目？ 这是我的用户信息

@Entity 公共类UserInformation实现Serializable {

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

@Override
public int hashCode() {
    int hash = 0;
    hash += (id != null ? id.hashCode() : 0);
    return hash;
}

@Override
public boolean equals(Object object) {
    // TODO: Warning - this method won't work in the case the id fields are not set
    if (!(object instanceof UserInformation)) {
        return false;
    }
    UserInformation other = (UserInformation) object;
    if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
        return false;
    }
    return true;
}

@Override
public String toString() {
    return "Database.UserInformation[ id=" + id + " ]";
}

}

这是我的用户类

public class Users实现Serializable {

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String username;
private String password;

 @OneToOne
private UserInformation userInfo;

public UserInformation getUserInfo() {
    return userInfo;
}

public void setUserInfo(UserInformation userInfo) {
    this.userInfo = userInfo;
}

public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

@Override
public int hashCode() {
    int hash = 0;
    hash += (id != null ? id.hashCode() : 0);
    return hash;
}

@Override
public boolean equals(Object object) {
    // TODO: Warning - this method won't work in the case the id fields are not set
    if (!(object instanceof Users)) {
        return false;
    }
    Users other = (Users) object;
    if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
        return false;
    }
    return true;
}

@Override
public String toString() {
    return "Database.Users[ id=" + id + " ]";
}

}

Answer 1

${user.userInfo.name}

这将为您提供userInfo的值，如果它为您提供空值，则检查您的数据库是否为空。很高兴它奏效了。