需求
执行一个未知的SQL,将其导出。SQL中可能含有CLOB字段。
SQL Map
<select id="selectSomething" parameterType="map" resultMap="PageData">
${sql_script}
</select>
java
思路:重写java.util.HashMap
,对CLOB字段进行处理。重写put()
方法。
import java.io.BufferedReader;
import java.io.Reader;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import com.alibaba.druid.proxy.jdbc.ClobProxyImpl;
/**
* 说明:参数封装Map
* 创建人:
* 修改时间:
* @version
*/
public class PageData extends HashMap implements Map{
private static final long serialVersionUID = 1L;
Map map = null;
HttpServletRequest request;
// public PageData(HttpServletRequest request){
// this.request = request;
// Map properties = request.getParameterMap();
// Map returnMap = new HashMap();
// Iterator entries = properties.entrySet().iterator();
// Map.Entry entry;
// String name = "";
// String value = "";
// while (entries.hasNext()) {
// entry = (Map.Entry) entries.next();
// name = (String) entry.getKey();
// Object valueObj = entry.getValue();
// if(null == valueObj){
// value = "";
// }else if(valueObj instanceof String[]){
// String[] values = (String[])valueObj;
// for(int i=0;i<values.length;i++){
// value = values[i] + ",";
// }
// value = value.substring(0, value.length()-1);
// }else{
// value = valueObj.toString();
// }
// returnMap.put(name, value);
// }
// map = returnMap;
// }
public PageData() {
map = new HashMap();
}
@Override
public Object get(Object key) {
Object obj = null;
if(map.get(key) instanceof Object[]) {
Object[] arr = (Object[])map.get(key);
obj = request == null ? arr:(request.getParameter((String)key) == null ? arr:arr[0]);
} else {
obj = map.get(key);
}
return obj;
}
public String getString(Object key) {
return (String)get(key);
}
@SuppressWarnings("unchecked")
@Override
public Object put(Object key, Object value) {
if(value instanceof ClobProxyImpl){ //读取oracle Clob类型数据
try {
ClobProxyImpl cpi = (ClobProxyImpl)value;
Reader is = cpi.getCharacterStream(); //获取流
BufferedReader br = new BufferedReader(is);
String str = br.readLine();
StringBuffer sb = new StringBuffer();
while(str != null){ //循环读取数据拼接到字符串
sb.append(str);
sb.append("\n");
str = br.readLine();
}
value = sb.toString();
} catch (Exception e) {
e.printStackTrace();
}
}
return map.put(key, value);
}
@Override
public Object remove(Object key) {
return map.remove(key);
}
public void clear() {
map.clear();
}
public boolean containsKey(Object key) {
// TODO Auto-generated method stub
return map.containsKey(key);
}
public boolean containsValue(Object value) {
// TODO Auto-generated method stub
return map.containsValue(value);
}
public Set entrySet() {
// TODO Auto-generated method stub
return map.entrySet();
}
public boolean isEmpty() {
// TODO Auto-generated method stub
return map.isEmpty();
}
public Set keySet() {
// TODO Auto-generated method stub
return map.keySet();
}
@SuppressWarnings("unchecked")
public void putAll(Map t) {
// TODO Auto-generated method stub
map.putAll(t);
}
public int size() {
// TODO Auto-generated method stub
return map.size();
}
public Collection values() {
// TODO Auto-generated method stub
return map.values();
}
}
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