Java 如何获得所有具有相同模式的字符串
我有一个具有这种结构的xml文件Java 如何获得所有具有相同模式的字符串,java,string,regression,Java,String,Regression,我有一个具有这种结构的xml文件 <expression>[Customer ].[Sales ].[L_MOIS]</expression><expression>cast_varchar([Customer ].[Sales ].[L_MOIS_ANNEE]) + ' ' + cast_varchar([Customer ].[Sales ].[C_ANNEE])</expression></dataItem></selec
<expression>[Customer ].[Sales ].[L_MOIS]</expression><expression>cast_varchar([Customer ].[Sales ].[L_MOIS_ANNEE])
+ ' ' +
cast_varchar([Customer ].[Sales ].[C_ANNEE])</expression></dataItem></selection><detailFilters><detailFilter><filterExpression>[Customer ].[Sales ].[DT_JOUR] <= getdate()</filterExpression></detailFilter></detailFilters></query><query name="RSmag"><source><model /></source><selection><dataItem aggregate="none" name="Code magasin"><expression>[Customer statistics].[Stores].[C_MAGASIN]</expression></dataItem><dataItem aggregate="none" name="Libellé magasin" sort="ascending"><expression>[Customer statistics].[Stores].[L_MAGASIN]</expression></dataItem></selection><detailFilters><detailFilter><filterExpression>[Customer statistics].[Stores].[C_DEPOT] <>'500'</filterExpression></detailFilter><detailFilter><filterExpression>[Customer statistics].[Stores].[C_MAGASIN] not in ('005120';'005130';'005140')</filterExpression></detailFilter></detailFilters>
</query><query name="CAdept_avec_metier_cumul"><source><model /></source><selection><dataItem aggregate="none" name="Cod Metier" rollupAggregate="none"><expression>[Customer ].[Articles].[COD_DPTG]</expression></dataItem><dataItem name="Nombre de tickets" rollupAggregate="total">
<expression>count(distinct [Customer ].[Sales ].[ID_TICKET])</expression></dataItem><dataItem name="Nombre de tickets non affecté" rollupAggregate="total"><expression>count(distinct
(case
when [Customer ].[Sales ].[C_AFFECTATION] <> 1
then [Customer ].[Sales ].[ID_TICKET]
else null
end)
)</expression>
将问题分为两部分: 1) 使用合适的XML解析器解析XML数据,以提取所需的文本 2) 对于提取的文本字段,使用正则表达式提取所需的子字符串 下面的示例使用SAX解析器(顺便说一下,我使用的是Java13) 假设我们有一个包含以下XML的文件:
<root>
<query name="RSmag">
<source>
<model />
</source>
<selection>
<dataItem aggregate="none" name="Code magasin">
<expression>
[Customer ].[Sales ].[L_MOIS]
</expression>
<expression>
cast_varchar([Customer ].[Sales ].[L_MOIS_ANNEE]) + ' ' + cast_varchar([Customer ].[Sales ].[C_ANNEE])
</expression>
</dataItem>
</selection>
<detailFilters>
<detailFilter>
<filterExpression>
[Customer ].[Sales ].[DT_JOUR] <= getdate()
</filterExpression>
</detailFilter>
</detailFilters>
</query>
<query name="RSmag">
<source>
<model />
</source>
<selection>
<dataItem aggregate="none" name="Code magasin">
<expression>
[Customer statistics].[Stores].[C_MAGASIN]
</expression>
</dataItem>
<dataItem aggregate="none" name="Libellé magasin" sort="ascending">
<expression>
[Customer statistics].[Stores].[L_MAGASIN]
</expression>
</dataItem>
</selection>
<detailFilters>
<detailFilter>
<filterExpression>
[Customer statistics].[Stores].[C_DEPOT] <> '500'
</filterExpression>
</detailFilter>
<detailFilter>
<filterExpression>
[Customer statistics].[Stores].[C_MAGASIN]
not in ('005120';'005130';'005140')
</filterExpression>
</detailFilter>
</detailFilters>
</query>
<query name="CAdept_avec_metier_cumul">
<source>
<model />
</source>
<selection>
<dataItem aggregate="none" name="Cod Metier" rollupAggregate="none">
<expression>
[Customer ].[Articles].[COD_DPTG]
</expression>
</dataItem>
<dataItem name="Nombre de tickets" rollupAggregate="total">
<expression>
count(distinct [Customer ].[Sales ].[ID_TICKET])
</expression>
</dataItem>
<dataItem name="Nombre de tickets non affecté" rollupAggregate="total">
<expression>count(distinct
(case
when [Customer ].[Sales ].[C_AFFECTATION] <> 1
then [Customer ].[Sales ].[ID_TICKET]
else null
end)
)
</expression>
</dataItem>
</selection>
</query>
</root>
步骤2-应用正则表达式
对于这些字符串中的每一个,我们都使用正则表达式来查找所需的数据:
\[.*?\](\.\[.*?\])*
这将搜索一个开头“[”,直到下一个“]”,并对零个或多个由句点分隔的后续“[”和“]”字符串重复此操作
为了处理不需要的子匹配,我们只保留组0:
Matcher m = pattern.matcher(text);
while (m.find()) {
System.out.println("*** Matches found : " + m.group(0));
}
这给了我们以下12个结果:
[Customer ].[Sales ].[L_MOIS]
[Customer ].[Sales ].[L_MOIS_ANNEE]
[Customer ].[Sales ].[C_ANNEE]
[Customer ].[Sales ].[DT_JOUR]
[Customer statistics].[Stores].[C_MAGASIN]
[Customer statistics].[Stores].[L_MAGASIN]
[Customer statistics].[Stores].[C_DEPOT]
[Customer statistics].[Stores].[C_MAGASIN]
[Customer ].[Articles].[COD_DPTG]
[Customer ].[Sales ].[ID_TICKET]
[Customer ].[Sales ].[C_AFFECTATION]
[Customer ].[Sales ].[ID_TICKET]
全解
import javax.xml.parsers.SAXParser;
导入javax.xml.parsers.SAXParserFactory;
导入org.xml.sax.Attributes;
导入org.xml.sax.SAXException;
导入org.xml.sax.helpers.DefaultHandler;
导入java.util.Set;
导入java.util.HashSet;
导入java.util.regex.Pattern;
导入java.util.regex.Matcher;
使用SAX解析来自文件的公共类{
//查找带有
//可选“.”将项目串到一个组中。
Pattern=Pattern.compile(\\[.\\\](\\.\\[.\.\\]])*”;
公共void parseUsingSax(){
试一试{
SAXParserFactory=SAXParserFactory.newInstance();
SAXParser SAXParser=factory.newSAXParser();
//我们将检查的标签(将跳过所有其他标签):
Set watchedElements=new HashSet();
添加(“表达式”);
watchedElements.add(“filterExpression”);
DefaultHandler=新的DefaultHandler(){
private boolean inement=false;
私人StringBuilder StringBuilder;
@凌驾
public void startElement(字符串uri、字符串localName、字符串name、,
属性)引发SAX异常{
if(watchedElements.contains(name)){
不合格=正确;
stringBuilder=新的stringBuilder();
}
}
@凌驾
公共无效字符(char[]缓冲区、int start、int length)引发异常{
if(非水泥){
追加(缓冲区、开始、长度);
}
}
@凌驾
public void endElement(字符串uri、字符串localName、,
字符串名称)引发异常{
if(watchedElements.contains(name)){
不合格=不合格;
String extractedText=formatString(stringBuilder.toString());
System.out.println();
System.out.println(“提取的XML文本:“+extractedText”);
打印匹配(提取文本);
}
}
};
parse(“C:/tmp/query_data.xml”,handler);
}捕获(例外e){
系统错误打印(e);
}
}
私有字符串格式字符串(字符串文本){
text=text.replaceAll(“\\r\\n |\\r |\\n”,”“);//删除换行符
text=text.replaceAll(“*”,“”);//折叠多个空格
return text.trim();//删除前导/尾随空格
}
私有void打印匹配(字符串文本){
Matcher m=模式匹配器(文本);
while(m.find()){
System.out.println(“***找到匹配项:”+m.group(0));
}
}
}
不要对xml文档使用正则表达式,请使用类似XPathShow的xml解析器来显示示例输入文件
Matcher m = pattern.matcher(text);
while (m.find()) {
System.out.println("*** Matches found : " + m.group(0));
}
[Customer ].[Sales ].[L_MOIS]
[Customer ].[Sales ].[L_MOIS_ANNEE]
[Customer ].[Sales ].[C_ANNEE]
[Customer ].[Sales ].[DT_JOUR]
[Customer statistics].[Stores].[C_MAGASIN]
[Customer statistics].[Stores].[L_MAGASIN]
[Customer statistics].[Stores].[C_DEPOT]
[Customer statistics].[Stores].[C_MAGASIN]
[Customer ].[Articles].[COD_DPTG]
[Customer ].[Sales ].[ID_TICKET]
[Customer ].[Sales ].[C_AFFECTATION]
[Customer ].[Sales ].[ID_TICKET]
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import java.util.Set;
import java.util.HashSet;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class ParseFromFileUsingSax {
// Looks for an opening "[" followed by a closing "]" with an
// optional "." to string items together into one group.
Pattern pattern = Pattern.compile("\\[.*?\\](\\.\\[.*?\\])*");
public void parseUsingSax() {
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser saxParser = factory.newSAXParser();
// the tags we will inspect (all others will be skipped):
Set<String> watchedElements = new HashSet();
watchedElements.add("expression");
watchedElements.add("filterExpression");
DefaultHandler handler = new DefaultHandler() {
private boolean inElement = false;
private StringBuilder stringBuilder;
@Override
public void startElement(String uri, String localName, String name,
Attributes attributes) throws SAXException {
if (watchedElements.contains(name)) {
inElement = true;
stringBuilder = new StringBuilder();
}
}
@Override
public void characters(char[] buffer, int start, int length) throws SAXException {
if (inElement) {
stringBuilder.append(buffer, start, length);
}
}
@Override
public void endElement(String uri, String localName,
String name) throws SAXException {
if (watchedElements.contains(name)) {
inElement = false;
String extractedText = formatString(stringBuilder.toString());
System.out.println();
System.out.println("Extracted XML text : " + extractedText);
printMatches(extractedText);
}
}
};
saxParser.parse("C:/tmp/query_data.xml", handler);
} catch (Exception e) {
System.err.print(e);
}
}
private String formatString(String text) {
text = text.replaceAll("\\r\\n|\\r|\\n", " "); // remove newlines
text = text.replaceAll(" *", " "); // collapse multiple spaces
return text.trim(); // remove leading/trailing whitespace
}
private void printMatches(String text) {
Matcher m = pattern.matcher(text);
while (m.find()) {
System.out.println("*** Matches found : " + m.group(0));
}
}
}