Java读写CSV格式文件（opencsv）

使用opencsv(opencsv-2.3.jar)，下载地址：http://download.csdn.net/detail/jinwufeiyang/9664120

一，读取CSV格式文件：

    import java.io.File;  
    import java.io.FileReader;  
    import java.util.List;  

    import au.com.bytecode.opencsv.CSVReader;  

    public class ReadCSV {  
        public static void main(String[] args) throws Exception {  
            File file = new File("e:\\read.csv");  
            FileReader fReader = new FileReader(file);  
            CSVReader csvReader = new CSVReader(fReader);  
            String[] strs = csvReader.readNext();  
            if(strs != null && strs.length > 0){  
                for(String str : strs)  
                    if(null != str && !str.equals(""))  
                        System.out.print(str + " , ");  
                System.out.println("\n---------------");  
            }  
            List<String[]> list = csvReader.readAll();  
            for(String[] ss : list){  
                for(String s : ss)  
                    if(null != s && !s.equals(""))  
                        System.out.print(s + " , ");  
                System.out.println();  
            }  
            csvReader.close();  
        }  
    }  

执行结果如下：

CSVReader.close()方法本质上是关闭传入其中的FileReader：

    private BufferedReader br;  

    public CSVReader(Reader reader, char separator, char quotechar,   
            char escape, int line, boolean strictQuotes, boolean ignoreLeadingWhiteSpace) {  
        this.br = new BufferedReader(reader);  
        this.parser = new CSVParser(separator, quotechar, escape,   
                strictQuotes, ignoreLeadingWhiteSpace);  
        this.skipLines = line;  
    }  

    public void close() throws IOException{  
        br.close();  
    }  

当然分隔符可以不是默认的逗号，只需在创建CSVReader时指定其分隔符即可：

    CSVReader csvReader = new CSVReader(fReader, ';');  

二，写CSV格式文件：

    import java.io.File;  
    import java.io.FileWriter;  
    import java.io.Writer;  

    import au.com.bytecode.opencsv.CSVWriter;  

    public class WriteCSV {  
        public static void main(String[] args) throws Exception {  
            File file = new File("e:\\write.csv");  
            Writer writer = new FileWriter(file);  
            CSVWriter csvWriter = new CSVWriter(writer, ',');  
            String[] strs = {"abc" , "abc" , "abc"};  
            csvWriter.writeNext(strs);  
            csvWriter.close();  
        }  
    }  

执行结果如下：

CSVWrite的构造方法如下：

    public static final char DEFAULT_QUOTE_CHARACTER = '"';  

    public CSVWriter(Writer writer, char separator) {  
        this(writer, separator, DEFAULT_QUOTE_CHARACTER);  
    }  

双引号被用作默认的引用符（具体什么意思不清楚）

修改一下CSVReader的初始化方式：

    CSVWriter csvWriter = new CSVWriter(writer, ',' , '\\');  

CSVReader中使用的是CSVParser中的静态变量：

public static final char DEFAULT_QUOTE_CHARACTER = '"';  

public static final char DEFAULT_ESCAPE_CHARACTER = '\\'; 

但是在CSVWriter中：

public static final char DEFAULT_QUOTE_CHARACTER = '"';  

public static final char DEFAULT_ESCAPE_CHARACTER = '"'; 

看来应该是作者的疏忽