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Project number: BS-GX-069
1. Introduction to the environment
Locale: Java: jdk1.8
Database: Mysql: mysql5.7
Application server: Tomcat: tomcat8.5.31
Development tools: IDEA or eclipse
Development technology: Javaweb
2. Project Introduction
This project is based on Javaweb development and implementation of a campus epidemic management system. There are three types of roles for participants in system design: students, teachers, and administrators. Students can register information online, teachers are assigned accounts by administrators, and administrators are designated by system initialization.
Students can log in to the system to apply for leaving and returning to school online, submit personal body temperature data, and manage personal information. Teachers can log in to the system to approve the information submitted by students, and can also report their own health temperature data and modify personal information. After logging into the system, administrators can conduct basic data management of students, teachers, colleges, majors, and class information. They can also manage health information reported by students and teachers, manage application information for entering and leaving school, and count the number of people leaving school. See below for details.
3. System display
User login
Administrator management
Student information management
Faculty and staff management
College Management
Professional management
Class management
Health and body temperature collection management
School admission application management
School leaving application management
School leaving statistics
4. Core code display
package dao;
import util.threadlocal.LocalRequestContext;
import util.threadlocal.LocalRequestContextHolder;
import javax.servlet.http.HttpServletRequest;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
/**
* 继承自ArrayList 的实现，并实现分页代码的展示
* @param <E>
*/
public class Collect<E> extends ArrayList<E> {
// 总数
protected long count = 0;
// 当前分页
protected int page = -1;
// 分页总数
protected int pageCount = 0;
// 第一行起始位置 limit firstRow,listRows 即可
public int firstRow = 0;
// 取数据库的行数
public int listRows = 15;
// URL 规则
protected String urlRule = "";
// 表现层代码
private String info;
private Collect()
{
}
public String getUrlRule() {
return urlRule;
}
public String getInfo() {
return info;
}
/**
*
* @param count 总行数
* @param pagesize 一页展示多少条数据
*/
public Collect(long count , int pagesize )
{
this.listRows = pagesize;
this.count = count;
this.initLimit();
}
/**
*
* @param count 总行数
* @param pagesize 一页展示多少条数据
* @param page 当前页
*/
public Collect(long count , int pagesize , int page )
{
this.listRows = pagesize;
this.count = count;
this.page = page;
this.initLimit();
}
/**
* 初始化
*/
protected void initLimit()
{
// 取分页数有多少
double ceil = (double) this.count / (double)this.listRows;
// 分页页面总数
this.pageCount = this.count == 0 ? 0 : new Double(Math.ceil(ceil)).intValue();
// 取URL 规则
this.urlRule = getRequestUrlPath();
// 获取第一行的位置
firstRow = listRows*(page-1);
// 渲染分页代码
info = reader();
// 获取当前线程的Request
LocalRequestContext content = LocalRequestContextHolder.getLocalRequestContext();
HttpServletRequest res = content.getRequest();
// 赋值给模版，模版采用 ${info.page} 即可显示分页
HashMap p = new HashMap();
p.put("info" , info);
//PageCollect p = new PageCollect();
//p.setInfo(info);
res.setAttribute("page" , p);
}
public long getCount()
{
return count;
}
public void setCount(long c)
{
this.count = c;
}
/**
* 渲染页面展示函数
* @return
*/
public String reader()
{
// 初始化字符串缓冲区
StringBuffer buffer = new StringBuffer();
// 替换URL 规则
String url = urlRule.replace("page={page}" , "");
// 生成表单
buffer.append("<form action=\""+url+"\" method=\"get\"><div class=\"pages\">");
buffer.append("<span>共").append(this.count).append("条").append(" ");
buffer.append(this.page).append("/").append(this.pageCount).append("页</span>");
// 渲染第一页
getFirstPage(buffer);
// 渲染上一页
getPrevPage(buffer);
// 渲染页码 如： 1 2 3 4 5 这样
getCenterPage(buffer);
// 渲染下一页
getNextPage(buffer);
// 渲染最后一页
getLastPage(buffer);
// 渲染下拉框
getSelect(buffer);
buffer.append("</div></form>");
//int currentPage = ;
// 返回渲染好的HTML 代码
return buffer.toString();
}
/**
* 渲染下拉框
* @param buffer
*/
protected void getSelect(StringBuffer buffer)
{
buffer.append("<select name=\"page\" onchange=\"this.form.submit()\">");
for(int i=1;i<=pageCount;i++){
buffer.append("<option value='"+i+"'"+(page==i?" selected":"")+">"+i+"</option>");
}
buffer.append("</select>");
}
/**
* 渲染页码 如1、2、3、4、5
* @param buffer
*/
protected void getCenterPage(StringBuffer buffer)
{
// 取中间页面
int rollPage = 2;
int show_nums = rollPage * 2 +1;
int i=0;
if(pageCount <= show_nums){
for(i = 1;i<=pageCount;i++){
if(i == this.page){
buffer.append("<a href=\"javascript:;\" class=\"active\">"+i+"</a>");
}else{
buffer.append("<a href=\"").append(this.getUrlPath(i)).append("\">"+i+"</a>");
}
}
}else if(page < (1+rollPage)){
for(i = 1;i<=show_nums;i++){
if(i == page){
buffer.append("<a href=\"javascript:;\" class=\"active\">"+i+"</a>");
}else{
buffer.append("<a href=\"").append(this.getUrlPath(i)).append("\">"+i+"</a>");
}
}
}else if(page >= (pageCount - rollPage)){
for(i = pageCount - show_nums ; i <= pageCount ; i++){
if(i == page){
buffer.append("<a href=\"javascript:;\" class=\"active\">"+i+"</a>");
}else{
buffer.append("<a href=\"").append(this.getUrlPath(i)).append("\">"+i+"</a>");
}
}
}else{
int start_page = page - rollPage;
int end_page = page + rollPage;
for(i = start_page ; i<=end_page ; i++){
if(i == page){
buffer.append("<a href=\"javascript:;\" class=\"active\">"+i+"</a>");
}else{
buffer.append("<a href=\"").append(this.getUrlPath(i)).append("\">"+i+"</a>");
}
}
}
}
/**
* 渲染第一页
* @param buffer
*/
protected void getFirstPage(StringBuffer buffer)
{
buffer.append("<a href=\"").append(this.getUrlPath(1)).append("\">第一页</a>");
}
/**
* 渲染上一页
* @param buffer
*/
protected void getPrevPage(StringBuffer buffer)
{
if(this.page == 1){
getDisabledButton(buffer , "上一页");
}else{
buffer.append("<a href=\"").append(getUrlPath(this.page - 1)).append("\">上一页</a>");
}
}
/**
* 渲染下一页
* @param buffer
*/
protected void getNextPage(StringBuffer buffer)
{
if(this.page < this.pageCount)
{
buffer.append("<a href=\"").append(getUrlPath(this.page + 1)).append("\">下一页</a>");
}else{
getDisabledButton(buffer , "下一页");
}
}
/**
* 渲染最后一页
* @param buffer
*/
protected void getLastPage(StringBuffer buffer)
{
buffer.append("<a href=\"").append(this.getUrlPath(this.pageCount)).append("\">尾页</a>");
}
/**
* 渲染不可点的按钮
* @param buffer
* @param name
*/
protected void getDisabledButton(StringBuffer buffer , String name)
{
buffer.append("<a href='javascript:;' class=\"disabled\">").append(name).append("</a>");
}
/**
* 获取替换成功的页码
* @param page
* @return
*/
protected String getUrlPath(int page)
{
return this.urlRule.replace("{page}" , String.valueOf(page));
}
/**
* 根据当前页面生成URL规则，
* @return
*/
protected String getRequestUrlPath()
{
// 获取当前线程的Request
LocalRequestContext context = LocalRequestContextHolder.getLocalRequestContext();
// 取 URL 后面的参数如： a=b&b=c&d=e
String queryString = context.getRequest().getQueryString();
if(queryString == null){
queryString = "";
}
// 创建缓冲区
StringBuffer buffer = new StringBuffer(queryString.length()+16);
// 获取URL path 参数如： /index.jsp
String requestURI = context.getRequest().getRequestURI();
// 开始写入参数
buffer.append(requestURI).append("?");
// 获取URL提交的参数
Map<String,String[]> param = context.getRequest().getParameterMap();
String name = "";
String value = "";
// 是否搜索page 参数
boolean isSearchPage = false;
int page = -1;
for (Map.Entry<String, String[]> entry : param.entrySet()) {
try{
name = entry.getKey();
String[] values = entry.getValue();
// 当前参数等于=page
if(name.equals("page")){
page = Integer.valueOf(values[0]).intValue();
// 写入url 规则的是：page={page} 使用时替换{page}即可
buffer.append(name).append("=").append("{page}").append("&");
isSearchPage = true;
} else if (null == values) {
// 值等于null,所以也写入
buffer.append(name).append("=").append("&");
} else if (values.length>1) {
// 同名参数，多个
for (int i = 0; i < values.length; i++) { //用于请求参数中有多个相同名称
value = URLEncoder.encode(values[i] , "UTF-8");
buffer.append(name).append("=").append(value).append("&");
}
//value = value.substring(0, value.length() - 1);
} else {
value = URLEncoder.encode(values[0] , "UTF-8");
buffer.append(name).append("=").append(value).append("&");//用于请求参数中请求参数名唯一
}
}catch (UnsupportedEncodingException e){
e.printStackTrace();
}
}
// 写入当前页码
if(this.page == -1){
this.page = page;
}
// 防止page 小于1
this.page = Math.max(this.page , 1);
// 没有搜索到页码直接写入
if(!isSearchPage){
buffer.append("page={page}&");
}
String result = buffer.toString();
return result.substring(0 , result.length()-1);
}
public int getPage() {
return page;
}
}
package dao;
import dao.db.Builder;
import util.Info;
import util.StringUtil;
import java.sql.*;
import java.util.*;
/**
* 操作数据库链式执行
* 目前只实现了部分方法，之后会继续完善该代码,让其支持实体类的数据获取
* 使用方法：Query.make("表名称").where("字段名" , "条件符号","条件值").select()
*
*/
public class Query {
protected String mName = "";
protected HashMap mOption = null;
protected String pk = "id";
protected HashMap mData = null;
protected Builder builder = null;
public static HashMap tableFields = new HashMap();
public Query()
{
reset();
}
/**
* 构造Query
* @param name
*/
public Query(String name)
{
reset();
setName(name);
}
/**
* 重置并初始化数据
* @return
*/
protected Query reset()
{
mName = "";
mOption = null;
mOption = new HashMap();
mData = new HashMap();
builder = Builder.make(new CommDAO().getConn());
if(tableFields == null)
{
tableFields = new HashMap();
}
return this;
}
/**
* 设置一个字段自增
* @param field
* @param step
* @return
*/
public Query inc(String field , int step)
{
if(step<1)step = 1;
ArrayList list = new ArrayList();
list.add("inc");
list.add(step);
mData.put(field , list);
return this;
}
/**
* 设置一个字段自减
* @param field
* @param step
* @return
*/
public Query dec(String field , int step)
{
if(step<1)step = 1;
ArrayList list = new ArrayList();
list.add("dec");
list.add(step);
mData.put(field , list);
return this;
}
/**
* 马上更新数据字段自增1
* @param field
* @return
*/
public boolean setInc(String field)
{
return setInc(field ,1);
}
/**
* 马上更新数据字段自增step
* @param field
* @param step
* @return
*/
public boolean setInc(String field , String step)
{
return inc(field , Integer.valueOf(step).intValue()).update();
}
/**
* 马上更新数据字段自增step
* @param field
* @param step
* @return
*/
public boolean setInc(String field , int step)
{
return inc(field , step).update();
}
/**
* 马上更新数据字段自减1
* @param field
* @return
*/
public boolean setDec(String field )
{
return setDec(field , 1);
}
/**
* 马上更新数据字段自减step
* @param field
* @param step
* @return
*/
public boolean setDec(String field , String step)
{
return dec(field , Integer.valueOf(step).intValue()).update();
}
/**
* 马上更新数据字段自减step
* @param field
* @param step
* @return
*/
public boolean setDec(String field , int step)
{
return dec(field , step).update();
}
/**
* 设置某字段为某个值，并更新
* @param field
* @param step
* @return
*/
public boolean setField(String field , Object step)
{
mData.put(field , step);
return update();
}
/**
* 获取当前写入的data
* @return
*/
public HashMap getData()
{
return mData;
}
/**
* 更新当前数据
* @return
*/
public boolean update()
{
return update(null);
}
/**
* 更新当前数据加写入的data
* @param updateData
* @return
*/
public boolean update( HashMap updateData )
{
if(updateData != null){
mData.putAll(updateData);
}
String sql = builder.buildUpdate(this);
executeInsert(sql);
return true;
}
/**
* 向query 写入data
* @param data
* @return
*/
public Query data(Map data)
{
mData.putAll(data);
return this;
}
/**
* 向当前query 写入data
* @param name
* @param value
* @return
*/
public Query data(String name , String value)
{
mData.put(name , value);
return this;
}
/**
* 向当前query 写入data
* @param name
* @param value
* @return
*/
public Query data(String name , int value)
{
mData.put(name , value);
return this;
}
/**
* 向当前query 写入data
* @param name
* @param value
* @return
*/
public Query data(String name , long value)
{
mData.put(name , value);
return this;
}
/**
* 向当前query 写入data
* @param name
* @param value
* @return
*/
public Query data(String name , float value)
{
mData.put(name , value);
return this;
}
/**
* 向当前query 写入data
* @param name
* @param value
* @return
*/
public Query data(String name , double value)
{
mData.put(name , value);
return this;
}
/**
* 向当前query 写入data
* @param name
* @param value
* @return
*/
public Query data(String name , boolean value)
{
mData.put(name , value ? 1 : 0);
return this;
}
/**
* 插入数据
* @param insertData
* @return
*/
public int insert(HashMap insertData ){ return insert(insertData , false); }
/**
* 插入数据
* @param insertData
* @param replace
* @return
*/
public int insert(HashMap insertData , boolean replace)
{
if(insertData != null){
mData.putAll(insertData);
}
String sql = builder.buildInsert(this , replace);
return executeInsert(sql);
}
/**
* 获取当前自增字段名称
* @return
*/
public String getPk() {
return pk;
}
/**
* 设置自增字段名
* @param pk
*/
public void setPk(String pk) {
this.pk = pk;
}
/**
* 尚未实现该代码，获取表的数据
*/
protected void finalize()
{
//Statement st = conn.createStatement();
//System.out.print(sql);
//ResultSet rs
//super.finalize();
free();
}
/**
* 释放资源
*/
public void free()
{
// 释放rs
for(int i=0;i<resultSetList.size();i++){
Object os = resultSetList.get(i);
try{
if(os instanceof Statement){
Statement st = ((Statement) os);
st.close();
}else if(os instanceof ResultSet){
((ResultSet) os).close();
}
}catch (SQLException e){
}
}
resultSetList.clear();
}
/**
* 设置表名称
* @param name
* @return
*/
public Query setName(String name)
{
mName = name;
return this;
}
/**
* 获取表名称
* @return
*/
public String getName()
{
return mName;
}
/**
* 设置属性
* @param name
* @param value
* @return
*/
public Query setAttribute(String name , Object value)
{
getOptionHashMap("data").put(name , value);
return this;
}
/**
* 获取属性
* @param name
* @return
*/
public Object getAttribute(String name)
{
return getOptionHashMap("data").get(name);
}
/**
* 设置字段为 获取所有字段
* @return
*/
public Query field()
{
return field("*");
}
/**
* 设置字段，可以用","逗号隔开多个
* @param field
* @return
*/
public Query field(String field)
{
getOptionArrayList("field").add(field);
return this;
}
/**
* 设置表
* @param nTable
* @return
*/
public Query table(String nTable)
{
getOptionArrayList("table").add(nTable);
return this;
}
/**
* 设置表
* @param nTable
* @return
*/
public Query table(String nTable , String alias)
{
getOptionArrayList("table").add(nTable+" "+alias);
return this;
}
/**
* 设置行数
* @param nLimit
* @return
*/
public Query limit(int nLimit)
{
//getOptionHashMap("limit").put("limit" , String.valueOf(nLimit));
return limit(String.valueOf(nLimit));
}
/**
* 设置起始行和行数
* @param offset
* @param nLimit
* @return
*/
public Query limit(int offset , int nLimit)
{
return limit(String.valueOf(offset) , String.valueOf(nLimit));
}
/**
* 设置是否锁表
* @param lock
* @return
*/
public Query lock( boolean lock )
{
return this.lock(lock ? " FOR UPDATE " : "");
}
/**
* 设置锁表代码
* @param lock
* @return
*/
public Query lock(String lock)
{
getOption().put("lock" , lock);
return this;
}
/**
* 设置行数，字符串形式
* @param nLimit
* @return
*/
public Query limit(String nLimit)
{
if(nLimit.indexOf(",") != -1){
String[] list = nLimit.split(",");
return limit(list[0] , list[1]);
}
getOptionHashMap("limit").put("limit" , nLimit);
return this;
}
/**
* 设置起始行和行数
* @param offset
* @param nLimit
* @return
*/
public Query limit(String offset , String nLimit)
{
HashMap map = getOptionHashMap("limit");
map.put("limit" , nLimit);
map.put("offset" , offset);
return this;
}
/**
* 根据ID 获取一行数据
* @param id
* @return
*/
public HashMap find(int id)
{
where(pk , String.valueOf(id));
return find();
}
/**
* 根据ID 获取一行数据
* @param id
* @return
*/
public HashMap find(String id)
{
where(pk , id);
return find();
}
/**
* 根据当前条件获取一行数据
* @return
*/
public HashMap find()
{
//limit(1);
String sql = builder.buildSelect(this);
ResultSet rs = query(sql);
QueryData data = fetch(rs);
return data;
}
/**
* 生成统计计算语句
* @param f
* @param func
* @return
*/
protected double total(String f , String func)
{
String ifnull = builder.parseIfNull(func+"("+f+")" , "0");
String field = ifnull+" count";
if(mOption.containsKey("field")){
getOptionArrayList("field").clear();
}
getOptionArrayList("field").add(field);
HashMap data = find();
if(data.containsKey("count")){
String count = data.get("count").toString();
return Double.valueOf(count).doubleValue();
}
return 0;
}
/**
* 求某字段和
* @param field
* @return
*/
public double sum(String field)
{
return total(field , "SUM");
}
/**
* 求某字段的平均值
* @param field
* @return
*/
public double avg(String field)
{
return total(field , "AVG");
}
/**
* 求最大值
* @param field
* @return
*/
public double max(String field){
return total(field , "MAX");
}
/**
* 求最小值
* @param field
* @return
*/
public double min(String field)
{
return total(field , "MIN");
}
/**
* 求数据行数
* @return
*/
public long count()
{
return count(null);
}
/**
* 根据字段名求数据行数
* @return
*/
public long count( String field )
{
if(field == null){
if(mOption.containsKey("alias")){
field = "count("+mOption.get("alias")+".id) count";
}else{
field = "count(*) count";
}
}else{
field = "count("+field+") count";
}
if(mOption.containsKey("field")){
mOption.put("field" , new ArrayList());
//getOptionArrayList("field").clear();
}
if(mOption.containsKey("order")){
mOption.remove("order");
}
getOptionArrayList("field").add(field);
HashMap data = find();
if(data.containsKey("count")){
return Long.valueOf((String)data.get("count")).longValue();
}
return 0;
}
/**
* 根据列表id 删除数据
* @param ids
* @return
*/
public long delete(List ids)
{
where(getPk() , "in" , ids);
return delete();
}
/**
* 根据id 删除数据
* @param id
* @return
*/
public long delete(int id)
{
where(getPk() , id);
return delete();
}
/**
* 根据id 删除数据
* @param id
* @return
*/
public long delete(String id)
{
if(id.indexOf(",")!=-1){
where(getPk() , "in" , id);
}else{
where(getPk() , id);
}
return delete();
}
/**
* 根据当前条件删除数据，如果没有条件则不执行删除
* @return
*/
public long delete()
{
if(!mOption.containsKey("where")){
return -1;
}
String sql = this.builder.buildDelete(this);
return executeUpdate(sql);
}
/**
* 根据当前条件获取数据集
* @return
*/
public ArrayList select()
{
ArrayList result = new ArrayList();
String sql = builder.buildSelect(this);
ResultSet rs = query(sql);
if (rs == null) {
return result;
}
QueryData data = null;
while( !((data = fetch(rs)).isEmpty()) ){
result.add(data);
}
return result;
}
/**
* 根据ResultSet 获取数据行
* @param rs
* @return
*/
public QueryData fetch(ResultSet rs)
{
QueryData data = new QueryData();
if(rs == null)return data;
try {
if(rs.next()){
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
for(int i=1;i<=columnCount;i++){
String name = rsmd.getColumnName(i);
String value = rs.getString(i);
if(value == null || value.toLowerCase().equals("null")){
value = "";
}
data.put(name , value);
}
}
}catch (SQLException sql){
sql.printStackTrace();
}
return data;
}
protected ArrayList resultSetList = new ArrayList();
/**
* 查询sql 语句并返回ResultSet，这个不需要释放，系统在释放时会自动释放
* @param sql
* @return
*/
public ResultSet query(String sql)
{
try {
Connection conn = this.getConn();
Statement st = conn.createStatement();
System.out.println(sql);
ResultSet rs = st.executeQuery(sql);
resultSetList.add(rs);
resultSetList.add(st);
return rs;
}catch (SQLException e){
int code = e.getErrorCode();
String message = e.getMessage();
System.err.println("SQL execute Error");
System.err.println("code:"+code);
System.err.println("Message:"+message);
//e.printStackTrace();
}
return null;
}
/**
* 根据当前条件获取一行数据中的某个字段的值
* @param name
* @return
*/
public String value(String name)
{
if(!mOption.containsKey("field")){
field(name);
}
HashMap data = find();
if(data.isEmpty()){
return "";
}
return String.valueOf(data.get(name));
}
/**
* 设置SQL 分组
* @param nGroup
* @return
*/
public Query group(String nGroup)
{
getOptionArrayList("group").add(nGroup);
return this;
}
/**
* 设置 SQL 排序字段
* @param nOrder
* @return
*/
public Query order(String nOrder)
{
getOptionArrayList("order").add(nOrder);
return this;
}
/**
* 设置SQL语句使用全连接 会生成如下：INNER JOIN table t on cond 的形式
* @param table
* @param cond 条件
* @return
*/
public Query joinInner(String table , String cond)
{
return join(table , cond , "INNER");
}
/**
* 设置sql 语句使用右连接 会生成如下：RIGHT JOIN table t on cond 的形式
* @param table
* @param cond
* @return
*/
public Query joinRight(String table , String cond)
{
return join(table , cond , "RIGHT");
}
/**
* 设置sql 语句使用左连接 会生成如下：table t on cond 的形式
* @param table
* @param cond
* @return
*/
public Query joinLeft(String table , String cond)
{
return join(table , cond , "LEFT");
}
/**
* 设置sql 语句使用右连接 会生成如下：type JOIN table t on cond 的形式
* @param table
* @param cond
* @param type 跨不会类型
* @return
*/
public Query join(String table , String cond , String type)
{
StringBuffer buffer = new StringBuffer();
buffer.append(" ").append(type).append(" JOIN ").append(table).append(" ON ").append(cond);
getOptionArrayList("join").add(buffer.toString());
return this;
}
/**
* 设置当前表的别名
* @param name
* @return
*/
public Query alias(String name)
{
mOption.put("alias" , name);
return this;
}
/**
* 获取设置参数
* @param type
* @return
*/
private HashMap getOptionHashMap(String type)
{
if(mOption.containsKey(type)){
return (HashMap) mOption.get(type);
}
HashMap map = new HashMap();
mOption.put(type , map);
return map;
}
/**
* 获取设置参数
* @param type
* @return
*/
private ArrayList getOptionArrayList(String type)
{
if(mOption.containsKey(type)){
return (ArrayList) mOption.get(type);
}
ArrayList map = new ArrayList();
mOption.put(type , map);
return map;
}
/**
* 设置SQL条件
* @param name
* @return
*/
public Query where(String name)
{
HashMap list = new HashMap();
list.put("where" , name);
getOptionArrayList("where").add(list);
return this;
}
/**
* 设置SQL条件 会自动写成 and name='value' 这样的形式
* @param name 字段名
* @param value 条件值
* @return
*/
public Query where(String name , Object value)
{
return where(name , null , value ,null);
}
/**
* 设置SQL条件 会自动写成 and name eq 'value' 这样的形式
* @param name
* @param eq 符号，可以写成：=、>、>=、<、<=、eq、neq、gt、egt、lt、elt
* @param value
* @return
*/
public Query where(String name ,String eq, Object value)
{
return where(name , eq , value ,null);
}
/**
* 设置SQL条件 会自动写成 and name eq 'value' 这样的形式
* @param name
* @param eq 符号，可以写成：=、>、>=、<、<=、eq、neq、gt、egt、lt、elt
* @param Value
* @param connect 连接符默认为：and
* @return
*/
public Query where(String name , String eq , Object Value , String connect)
{
HashMap list = new HashMap();
list.put("name",name);
list.put("exp" , eq == null ? "=" : eq);
list.put("value",Value == null ? "" : Value);
list.put("connect",connect == null ? "and" : connect);
getOptionArrayList("where").add(list);
return this;
}
/**
* 设置SQL条件 会自动写成 and field in(inArray) 这样的形式
* @param field
* @param inArray
* @return
*/
public Query whereIn(String field , String inArray)
{
String[] arr = inArray.split(",");
return where(field , "in" , arr);
}
/**
* 设置SQL条件 会自动写成 and field in(inArray1,inArray2) 这样的形式
* @param field
* @param inArray
* @return
*/
public Query whereIn(String field , Object inArray)
{
return where(field , "in" , inArray);
}
/**
* 设置SQL条件 会自动写成 and field not in(inArray1) 这样的形式
* @param field
* @param inArray
* @return
*/
public Query whereInNot(String field , Object inArray)
{
return where(field , "not in" , inArray);
}
/**
* 设置SQL条件 会自动写成 and field between inArray 这样的形式
* @param field
* @param inArray
* @return
*/
public Query whereBetween(String field , String inArray)
{
String[] arr = inArray.split(",");
return where(field , "between" , arr);
}
/**
* 设置SQL条件 会自动写成 and field between 'start' and 'end' 这样的形式
* @param field
* @param start
* @param end
* @return
*/
public Query whereBetween(String field , String start , String end)
{
return where(field , "between" , "'"+start+"' AND '"+end+"'");
}
/**
* 设置SQL条件 会自动写成 and field not between inArray 这样的形式
* @param field
* @param inArray
* @return
*/
public Query whereBetweenNot(String field , String inArray)
{
String[] arr = inArray.split(",");
return where(field , "not between" , arr);
}
/**
* 设置SQL条件 会自动写成 and field not between 'start' and 'end' 这样的形式
* @param field
* @param start
* @param end
* @return
*/
public Query whereBetweenNot(String field , String start , String end)
{
return where(field , "not between" , "'"+start+"' AND '"+end+"'");
}
/**
* 获取connection 连接
* @return
*/
protected Connection getConn()
{
return new CommDAO().getConn();
}
/**
* 根据字段类型生成默认值
* @param type
* @return
*/
protected String getFieldDefault(String type)
{
String t = type.toUpperCase();
if(t.equals("DATE")){
return "0000-00-00";
}else if(t.equals("DATETIME")){
return "0000-00-00 00:00:00";
}else if(t.equals("TIME")){
return "00:00:00";
}else if(t.equals("TIMESTAMP")){
return Info.getDateStr();
}else if(t.equals("FLOAT") || t.equals("DOUBLE") || t.equals("DECIMAL") || t.indexOf("INT")!=-1){
return "0";
}
return "''";
}
/**
* 设置字段信息防止xxs 注入
* @param type
* @param value
* @return
*/
protected String getFieldValue(String type , String value)
{
String t = type.toUpperCase();
if(value == null || value.equals("")){
// 等于空值，就写入默认值
return getFieldDefault(type);
}
if(t.equals("FLOAT") || t.equals("DOUBLE") || t.equals("DECIMAL") || t.indexOf("INT")!=-1){
return value;
}
return "'"+value.replace("'" , "\\'")+"'";
}
/**
* 获取表字段信息
* @param table
* @return
*/
protected HashMap getTableField(String table )
{
if(table == null){
table = mName;
}
if(tableFields.containsKey(table)){
return (HashMap) tableFields.get(table);
}
HashMap result = new HashMap();
try{
Connection conn = this.getConn();
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery("select * from " + table);
ResultSetMetaData rsmd = rs.getMetaData();
int i = rsmd.getColumnCount();
for (int j = 1; j <= i; j++) {
result.put(rsmd.getColumnName(j) , rsmd.getColumnTypeName(j));
}
rs.close();
st.close();
}catch (SQLException e){
e.printStackTrace();
}
return result;
}
/**
* 根据表字段生成键值 和 value值
* @param map 数据
* @param fields 空的字段信息
* @param values 空的value 值 也就是要写入的值，不需要传值
* @param isInsert 是否为插入，插入的话要写入默认值
*/
protected void getFieldValueList(HashMap map , ArrayList fields , ArrayList values , boolean isInsert)
{
try{
Connection conn = this.getConn();
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery("select * from " + mName);
ResultSetMetaData rsmd = rs.getMetaData();
int i = rsmd.getColumnCount();
for (int j = 1; j <= i; j++) {
String col =rsmd.getColumnName(j);
if (col.toLowerCase().equals("id")) continue;
String type = rsmd.getColumnTypeName(j);
if(map.containsKey(col)){
// 存在,就不理他了
fields.add(col);
values.add(getFieldValue(type ,String.valueOf(map.get(col))) );
}else{
// 插入的时候才将所有字段弄过去
if(isInsert){
fields.add(col);
values.add(getFieldDefault(type));
}
}
}
} catch (SQLException e) {
e.printStackTrace();
} catch (Exception e){
e.printStackTrace();
}
}
/**
* 添加数据
* @param map
* @return
*/
public String add( HashMap map )
{
ArrayList fields = new ArrayList();
ArrayList values = new ArrayList();
getFieldValueList(map , fields , values , true);
String field = StringUtil.join(",",fields);
String value = StringUtil.join("," , values);
String sql = "INSERT INTO "+mName+"("+field+") VALUES("+value+")";
int insertID = executeInsert(sql);
return insertID == -1 ? "" : String.valueOf(insertID);
}
/**
* 更新数据
* @param map
* @return
*/
public boolean save(HashMap map)
{
ArrayList fields = new ArrayList();
ArrayList values = new ArrayList();
getFieldValueList(map , fields , values , false);
ArrayList key2val = new ArrayList();
for(int i=0;i<fields.size();i++){
String field = (String)fields.get(i);
String value = (String)values.get(i);
key2val.add(field+"="+value);
}
ArrayList where = getOptionArrayList("where");
if(where.size() == 0 && map.containsKey(pk)){
this.where(pk , (String) map.get(pk));
}
if(where.size() == 0){
return false;
}
String sql = "UPDATE "+mName+" SET "+StringUtil.join("," , key2val)+" " + parseWhere(where);
executeInsert(sql);
return true;
}
/**
* 执行插入语句
* @param sql
* @return
*/
public int executeInsert(String sql)
{
try {
Connection conn = this.getConn();
Statement rs = conn.createStatement();
System.out.println(sql);
rs.executeUpdate(sql , Statement.RETURN_GENERATED_KEYS);
ResultSet rsKey = rs.getGeneratedKeys();
rsKey.next();
int id = rsKey.getInt(1);
return id;
}catch (SQLException e)
{
int code = e.getErrorCode();
String message = e.getMessage();
System.err.println("SQL execute Error");
System.err.println("code:"+code);
System.err.println("Message:"+message);
//e.printStackTrace();
}
return -1;
}
/**
* 执行更新语句
* @param sql
* @return
*/
public int executeUpdate(String sql)
{
try {
Connection conn = this.getConn();
Statement rs = conn.createStatement();
System.out.println(sql);
int id = rs.executeUpdate(sql , Statement.RETURN_GENERATED_KEYS);
return id;
}catch (SQLException e)
{
int code = e.getErrorCode();
String message = e.getMessage();
System.err.println("SQL execute Error");
System.err.println("code:"+code);
System.err.println("Message:"+message);
//e.printStackTrace();
}
return -1;
}
/**
* 快速构建Query
* @param name
* @return
*/
public static Query make(String name)
{
Query query = new Query();
query.setName(name);
return query;
}
/**
* 获取一页数据，并生成分页代码
* @param pagesize
* @return
*/
public Collect page( int pagesize )
{
Query c = new Query(getName());
c.mOption.putAll(mOption);
// 总长度
long count = c.count();
Collect result = new Collect( count , pagesize);
this.limit(result.firstRow , result.listRows);
builder.setPage(true);
ArrayList list = select();
builder.setPage(false);
result.addAll(list);
return result;
}
/**
* 解析条件
* @return
*/
protected String parseWhere()
{
if(!mOption.containsKey("where")){
return "";
}
return parseWhere(getOptionArrayList("where"));
}
/**
* 获取当前option
* @return
*/
public HashMap getOption() {
return mOption;
}
/**
* 解析条件
* @param whereList
* @return
*/
private String parseWhere(ArrayList whereList)
{
StringBuffer buffer = new StringBuffer();
for(int i=0;i<whereList.size();i++)
{
HashMap map = (HashMap) whereList.get(0);
if(i!=0){
// 每一个的连接符
buffer.append(" ");
buffer.append(map.get("connect"));
buffer.append(" ");
}
String key = (String) map.get("name");
String exp = (String) map.get("exp");
Object val = map.get("value");
if(-1 != key.indexOf("|")){
String[] keys = key.split("|");
buffer.append("(");
for(int j=0;j<keys.length;j++){
if(j!=0){
buffer.append(" OR ");
}
parseWhereItem(buffer , keys[j] , exp , val);
}
buffer.append(")");
}else{
parseWhereItem(buffer , key , exp , val);
}
}
if(buffer.length() > 0){
buffer.insert(0 , " where ");
}
return buffer.toString();
}
/**
* 根据当前条件，获取一列的数据
* @param field
* @return
*/
public List<String> getCol(String field)
{
List<String> result = new ArrayList();
// 取某一列
List<HashMap> list= select();
for (HashMap map:list){
result.add(map.get(field).toString());
}
return result;
}
/**
* 根据当前条件获取列数据,健对值的关系
* @param field
* @param key
* @return
*/
public Map<String ,String> getColkey(String field , String key)
{
Map result = new LinkedHashMap();
List<HashMap> list= select();
for (HashMap map:list){
result.put(map.get(key).toString(),map.get(field).toString());
}
return result;
}
/**
* 格式化字符串
* @param val
* @return
*/
private String formatString( String val)
{
return "'"+val.replace("'" , "\\'")+"'";
}
/**
* 解析where 条件子语句
* @param buffer
* @param key
* @param exp
* @param val
*/
private void parseWhereItem(StringBuffer buffer , String key , String exp , Object val)
{
List<String> exps = Arrays.asList("eq,neq,lt,elt,gt,egt".split(","));
int index = exps.indexOf(key);
String[] exps2 = "=,!=,<,<=,>,=>".split(",");
if(index != -1){
exp = exps2[index];
}
exp = exp.toLowerCase().trim();
if(exp.equals("in") || exp.equals("not in")){
ArrayList inArrayList = new ArrayList();
if(val instanceof String || val instanceof String[]){
String[] inList = val instanceof String ? ((String)val).split(",") : (String[]) val;
for (int i=0;i<inList.length;i++){
inArrayList.add(formatString(inList[i]));
}
}else if(val instanceof List){
for (int i=0;i<((List) val).size();i++)
{
inArrayList.add(formatString((String)((List) val).get(i)));
}
}else if(val instanceof int[]){
for (int i=0;i<((int[]) val).length;i++)
{
inArrayList.add(((int[]) val)[i]);
}
}else if(val instanceof float[]){
for (int i=0;i<((float[]) val).length;i++)
{
inArrayList.add(((float[]) val)[i]);
}
}else if(val instanceof double[]){
for (int i=0;i<((double[]) val).length;i++)
{
inArrayList.add(((double[]) val)[i]);
}
}else if(val instanceof long[]){
for (int i=0;i<((long[]) val).length;i++)
{
inArrayList.add(((long[]) val)[i]);
}
}
buffer.append(" ");
buffer.append(key);
buffer.append(" "+exp+"("+StringUtil.join("," , inArrayList)+") ");
}else{
buffer.append(" "+key);
buffer.append(" "+exp+" ");
buffer.append(formatString((String) val));
buffer.append(" ");
}
}
}
5. Display of related works
Practical projects based on Java development, Python development, PHP development, C# development and other related languages
Front-end practical projects developed based on Nodejs, Vue and other front-end technologies
Related works based on WeChat applet and Android APP application development
Development and application of embedded Internet of Things based on 51 microcontroller and other embedded devices
AI intelligent applications based on various algorithms
Various data management and recommendation systems based on big data
