自定义模版,避免出现Null pointer exception,让你的get和set方法更完美

朱雀 2020-10-24 16:40 519阅读 0赞

在开发时,我们都习惯用gsonformat自动生成javaBean来接收后台返回的数据,然而,很多时候,后台并未返回字段或者该字段为空,我们在调用时就会出现各种Null pointer exception,为了避免这个错误,其实生成get和set方法时,可以自定义模板如下:

本来的模板为:IntelliJ Default

研究发现,set和get方法可以根据&name和field.name来进性判断,于是尝试修改如下:

get方法:

#if($field.modifierStatic)
    static ##
    #end
    $field.type ##
    #set($name = $StringUtil.capitalizeWithJavaBeanConvention($StringUtil.sanitizeJavaIdentifier($helper.getPropertyName($field, $project))))
    #if ($field.boolean && $field.primitive)
      #if ($StringUtil.startsWithIgnoreCase($name, 'is'))
        #set($name = $StringUtil.decapitalize($name))
      #else
        is##
    #end
    #else
      get##
    #end
    ${name}() {
      #if ($field.string)
         return $field.name == null ? "" : $field.name;
      #else 
        #if ($field.list)
        if ($field.name == null) {
            return new ArrayList<>();
        }
        return $field.name;
        #else 
        return $field.name;
        #end
      #end
    }

set方法如下:

#set($paramName = $helper.getParamName($field, $project))
    public ##
    #if($field.modifierStatic)
      static ##
    #end
    void set$StringUtil.capitalizeWithJavaBeanConvention($StringUtil.sanitizeJavaIdentifier($helper.getPropertyName($field, $project)))($field.type $paramName) {
      #if ($field.name == $paramName)
        #if (!$field.modifierStatic)
          this.##
        #else
          $classname.##
        #end
      #end
      #if($field.string)
        $field.name = $paramName == null ? "" : $paramName;
      #else  
        $field.name = $paramName;
      #end
    }

如此便可生成如下代码:

public class ClassifyBean {
        private String msg;
        private int code;
        private boolean success;
        private List<DataBean> data;
    
        public String getMsg() {
            return msg == null ? "" : msg;
        }
    
        public void setMsg(String msg) {
            this.msg = msg == null ? "" : msg;
        }
    
        public int getCode() {
            return code;
        }
    
        public void setCode(int code) {
            this.code = code;
        }
    
        public boolean isSuccess() {
            return success;
        }
    
        public void setSuccess(boolean success) {
            this.success = success;
        }
    
        public List<DataBean> getData() {
            if (data == null) {
                return new ArrayList<>();
            }
            return data;
        }
    
        public void setData(List<DataBean> data) {
            this.data = data;
        }
    
        public static class DataBean {
            private String id;
            private String name;
            private String parentId;
            private int flag;
            private String thumbnail;
            private int isDelete;
            private int priority;
            private List<ChildrenBeanX> children;
    
            public String getId() {
                return id == null ? "" : id;
            }
    
            public void setId(String id) {
                this.id = id == null ? "" : id;
            }
    
            public String getName() {
                return name == null ? "" : name;
            }
    
            public void setName(String name) {
                this.name = name == null ? "" : name;
            }
    
            public String getParentId() {
                return parentId == null ? "" : parentId;
            }
    
            public void setParentId(String parentId) {
                this.parentId = parentId == null ? "" : parentId;
            }
    
            public int getFlag() {
                return flag;
            }
    
            public void setFlag(int flag) {
                this.flag = flag;
            }
    
            public String getThumbnail() {
                return thumbnail == null ? "" : thumbnail;
            }
    
            public void setThumbnail(String thumbnail) {
                this.thumbnail = thumbnail == null ? "" : thumbnail;
            }
    
            public int getIsDelete() {
                return isDelete;
            }
    
            public void setIsDelete(int isDelete) {
                this.isDelete = isDelete;
            }
    
            public int getPriority() {
                return priority;
            }
    
            public void setPriority(int priority) {
                this.priority = priority;
            }
    
            public List<ChildrenBeanX> getChildren() {
                if (children == null) {
                    return new ArrayList<>();
                }
                return children;
            }
    
            public void setChildren(List<ChildrenBeanX> children) {
                this.children = children;
            }
    
            public static class ChildrenBeanX {
                private String id;
                private String name;
                private String parentId;
                private int flag;
                private int isDelete;
                private int priority;
                private String thumbnail;
                private List<ChildrenBean> children;
    
                public String getId() {
                    return id == null ? "" : id;
                }
    
                public void setId(String id) {
                    this.id = id == null ? "" : id;
                }
    
                public String getName() {
                    return name == null ? "" : name;
                }
    
                public void setName(String name) {
                    this.name = name == null ? "" : name;
                }
    
                public String getParentId() {
                    return parentId == null ? "" : parentId;
                }
    
                public void setParentId(String parentId) {
                    this.parentId = parentId == null ? "" : parentId;
                }
    
                public int getFlag() {
                    return flag;
                }
    
                public void setFlag(int flag) {
                    this.flag = flag;
                }
    
                public int getIsDelete() {
                    return isDelete;
                }
    
                public void setIsDelete(int isDelete) {
                    this.isDelete = isDelete;
                }
    
                public int getPriority() {
                    return priority;
                }
    
                public void setPriority(int priority) {
                    this.priority = priority;
                }
    
                public String getThumbnail() {
                    return thumbnail == null ? "" : thumbnail;
                }
    
                public void setThumbnail(String thumbnail) {
                    this.thumbnail = thumbnail == null ? "" : thumbnail;
                }
    
                public List<ChildrenBean> getChildren() {
                    if (children == null) {
                        return new ArrayList<>();
                    }
                    return children;
                }
    
                public void setChildren(List<ChildrenBean> children) {
                    this.children = children;
                }
    
                public static class ChildrenBean {
                    private String id;
                    private String name;
                    private String parentId;
                    private int flag;
                    private int isDelete;
                    private int priority;
                    private String thumbnail;
                    private List<?> children;
    
                    public String getId() {
                        return id == null ? "" : id;
                    }
    
                    public void setId(String id) {
                        this.id = id == null ? "" : id;
                    }
    
                    public String getName() {
                        return name == null ? "" : name;
                    }
    
                    public void setName(String name) {
                        this.name = name == null ? "" : name;
                    }
    
                    public String getParentId() {
                        return parentId == null ? "" : parentId;
                    }
    
                    public void setParentId(String parentId) {
                        this.parentId = parentId == null ? "" : parentId;
                    }
    
                    public int getFlag() {
                        return flag;
                    }
    
                    public void setFlag(int flag) {
                        this.flag = flag;
                    }
    
                    public int getIsDelete() {
                        return isDelete;
                    }
    
                    public void setIsDelete(int isDelete) {
                        this.isDelete = isDelete;
                    }
    
                    public int getPriority() {
                        return priority;
                    }
    
                    public void setPriority(int priority) {
                        this.priority = priority;
                    }
    
                    public String getThumbnail() {
                        return thumbnail == null ? "" : thumbnail;
                    }
    
                    public void setThumbnail(String thumbnail) {
                        this.thumbnail = thumbnail == null ? "" : thumbnail;
                    }
    
                    public List<?> getChildren() {
                        if (children == null) {
                            return new ArrayList<>();
                        }
                        return children;
                    }
    
                    public void setChildren(List<?> children) {
                        this.children = children;
                    }
                }
            }
        }