//Here is sorted List alphabetically with syncronized
package com.mnas.technology.automation.utility;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;

import org.apache.log4j.Logger;
/**
* 
* @author manoj.kumar
*/
public class SynchronizedArrayList {
static Logger log = Logger.getLogger(SynchronizedArrayList.class.getName());
@SuppressWarnings("unchecked")
public static void main(String[] args) {

List<Employee> synchronizedList = Collections.synchronizedList(new ArrayList<Employee>());
synchronizedList.add(new Employee("Aditya"));
synchronizedList.add(new Employee("Siddharth"));
synchronizedList.add(new Employee("Manoj"));
Collections.sort(synchronizedList, new Comparator() {
public int compare(Object synchronizedListOne, Object synchronizedListTwo) {
//use instanceof to verify the references are indeed of the type in question
return ((Employee)synchronizedListOne).name
.compareTo(((Employee)synchronizedListTwo).name);
}
}); 
/*for( Employee sd : synchronizedList) {
log.info("Sorted Synchronized Array List..."+sd.name);
}*/

// when iterating over a synchronized list, we need to synchronize access to the synchronized list
synchronized (synchronizedList) {
Iterator<Employee> iterator = synchronizedList.iterator();
while (iterator.hasNext()) {
log.info("Sorted Synchronized Array List Items: " + iterator.next().name);
}
}

}
}
class Employee {
String name;
Employee (String name) {
this.name = name;

}
}

您可以使用Java 8 Stream或Guava创建一个新的排序副本:

// Java 8 version
List<String> sortedNames = names.stream().sorted().collect(Collectors.toList());
// Guava version
List<String> sortedNames = Ordering.natural().sortedCopy(names); 

另一种选择是通过Collections API就地排序:

Collections.sort(names);

你可以使用下面这行

集合。排序(listOfCountryNames String.CASE_INSENSITIVE_ORDER)

它类似于Thilo的建议，但不会区分大小写字符。

除非您只使用无重音的英文对字符串进行排序，否则您可能希望使用Collator。它将正确排序变音符符号，可以忽略大小写和其他特定于语言的东西:

Collections.sort(countries, Collator.getInstance(new Locale(languageCode)));

你可以设置排序器的强度，参见javadoc。

下面是一个斯洛伐克语的例子，Š应该在S后面，但在UTF中Š应该在Z后面。

List<String> countries = Arrays.asList("Slovensko", "Švédsko", "Turecko");

Collections.sort(countries);
System.out.println(countries); // outputs [Slovensko, Turecko, Švédsko]

Collections.sort(countries, Collator.getInstance(new Locale("sk")));
System.out.println(countries); // outputs [Slovensko, Švédsko, Turecko]

通过使用Collections.sort()，我们可以对列表进行排序。

public class EmployeeList {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        List<String> empNames= new ArrayList<String>();

        empNames.add("sudheer");
        empNames.add("kumar");
        empNames.add("surendra");
        empNames.add("kb");

        if(!empNames.isEmpty()){

            for(String emp:empNames){

                System.out.println(emp);
            }

            Collections.sort(empNames);

            System.out.println(empNames);
        }
    }
}

输出:

sudheer
kumar
surendra
kb
[kb, kumar, sudheer, surendra]

使用Collections.sort的两个参数。你会想要一个合适的比较器，处理大小写适当(即词法，而不是UTF16排序)，比如通过java.text.Collator.getInstance获得。