使用方法：https://www.cnblogs.com/csguo/p/7614893.html
擴(kuò)展一個(gè)JSTL表達(dá)式替換的方法 string.jstl：
import com.google.common.collect.Lists;
import com.googlecode.aviator.AviatorEvaluator;
import com.googlecode.aviator.Expression;
import com.googlecode.aviator.runtime.function.AbstractFunction;
import com.googlecode.aviator.runtime.function.FunctionUtils;
import com.googlecode.aviator.runtime.type.AviatorObject;
import com.googlecode.aviator.runtime.type.AviatorString;
import org.apache.commons.collections.CollectionUtils;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
/**
* TODO
*
* @author zecong.nian
* @since 2020/7/15
*/
public class StringReplaceJstlFunction extends AbstractFunction {
public final static Pattern pattern = Pattern.compile("\\$\\{([^}]+?)\\}");
@Override
public String getName() {
return "string.jstl";
}
@Override
public AviatorObject call(Map<String, Object> env, AviatorObject str, AviatorObject defaultResult) {
String text = FunctionUtils.getStringValue(str, env);
// 正則找到文案中包含的參數(shù)
List<String> params = Lists.newArrayList();
Matcher m = pattern.matcher(text);
while(m.find()){
params.add(m.group(1));
}
// 替換參數(shù)
for (String paramKey : params) {
String param = "${" + paramKey + "}";
if (text.contains(param) && env.containsKey(paramKey)) {
text = text.replace(param, String.valueOf(env.get(paramKey)));
}
}
if (pattern.matcher(text).find()){
return defaultResult;
} else {
return new AviatorString(text);
}
}
public static void main(String[] args) {
String text = "文案${abc}tihuan";
String defaultText = "文案def";
AviatorEvaluator.addFunction(new StringReplaceJstlFunction());
String expression = "string.jstl(_text_,_default_)";
Expression compiledExp = AviatorEvaluator.compile(expression);
Map<String, Object> params = new HashMap<>();
params.put("_text_", text);
params.put("_default_", defaultText);
params.put("abc", "123");
System.out.println(compiledExp.execute(params));
}
}
