csv格式读取通用类

csv格式读取通用类 - - ITeye技术网站

csv格式读取通用类

博客分类：
• java

需要添加javacsv.jar 支持

 

import static net.etongbao.common.utils.StringUtils.toStringWithOutNull;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.csvreader.CsvReader;
import com.csvreader.CsvWriter;

/**
 * 解析CSV文件
 *
 * @author Fu Wei
 *
 */
public class CsvUtils {
    /** 编码 */
    private static final String ENCODING = "UTF-8";

    private static final Logger LOG = LoggerFactory.getLogger(CsvUtils.class);

    /**
     * csv格式读
     *
     * @param String
     * @return List<Map<String, Object>>
     * @throws CsvException
     */
    public static List<Map<String, Object>> csvReader(String csvText) {
        List<Map<String, Object>> csvList = new ArrayList<Map<String, Object>>();
        try {
            CsvReader reader = CsvReader.parse(csvText);
            // 考虑到图片大小,设置最大长度不受限制
            reader.setSafetySwitch(false);
            String[] headers = null;
            if (reader.readHeaders()) {
                headers = reader.getHeaders();
                while (reader.readRecord()) {
                    Map<String, Object> csvMap = new HashMap<String, Object>();
                    for (String head : headers) {
                        csvMap.put(head, reader.get(head));
                    }
                    csvList.add(csvMap);
                }
                LOG.debug("CsvUtils--->csvList:{}", csvList);
                return csvList;
            } else {
                LOG.error("csv读取头失败");
            }
        } catch (UnsupportedEncodingException e) {
            LOG.error("csv读取编码异常");
        } catch (IOException e) {
            LOG.error("csv读取IO异常", e);
        }
        return null;
    }

    /**
     * csv写
     *
     * @param csvList
     * @return
     * @throws CsvException
     */
    public static String csvWriter(List<Map<String, Object>> csvList) {
        String csvText = null;
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        CsvWriter writer = new CsvWriter(stream, ',', Charset.forName(ENCODING));
        if (csvList != null && csvList.size() > 0) {
            // 获取第一行map key,
            Map<String, Object> headMap = csvList.get(0);

            if (headMap != null && 0 <= headMap.size()) {
                // 提取cvs列
                Iterator<String> it = headMap.keySet().iterator();
                try {
                    while (it.hasNext()) {
                        writer.write(it.next());
                    }
                    writer.endRecord();
                    boolean falg = false;
                    for (Map<String, Object> csvMap : csvList) {
                        if (falg) {
                            writer.endRecord();
                        }
                        for (Entry<String, Object> map : csvMap.entrySet()) {
                            String value = toStringWithOutNull(map.getValue());
                            writer.write(value);
                        }
                        falg = true;
                    }
                    writer.close();
                    csvText = stream.toString();
                    stream.close();
                    return csvText;
                } catch (IOException e) {
                    LOG.warn("csv写入IO异常");
                }
            } else {
                LOG.warn("拆解cvs数据为空");
            }
        } else {
            LOG.warn("拆解cvs数据为空");
        }
        return null;
    }

}

import static net.etongbao.common.utils.StringUtils.toStringWithOutNull;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.csvreader.CsvReader;
import com.csvreader.CsvWriter;

/**
 * 解析CSV文件
 *
 * @author Fu Wei
 *
 */
public class CsvUtils {
	/** 编码 */
	private static final String ENCODING = "UTF-8";

	private static final Logger LOG = LoggerFactory.getLogger(CsvUtils.class);

	/**
	 * csv格式读
	 *
	 * @param String
	 * @return List<Map<String, Object>>
	 * @throws CsvException
	 */
	public static List<Map<String, Object>> csvReader(String csvText) {
		List<Map<String, Object>> csvList = new ArrayList<Map<String, Object>>();
		try {
			CsvReader reader = CsvReader.parse(csvText);
			// 考虑到图片大小,设置最大长度不受限制
			reader.setSafetySwitch(false);
			String[] headers = null;
			if (reader.readHeaders()) {
				headers = reader.getHeaders();
				while (reader.readRecord()) {
					Map<String, Object> csvMap = new HashMap<String, Object>();
					for (String head : headers) {
						csvMap.put(head, reader.get(head));
					}
					csvList.add(csvMap);
				}
				LOG.debug("CsvUtils--->csvList:{}", csvList);
				return csvList;
			} else {
				LOG.error("csv读取头失败");
			}
		} catch (UnsupportedEncodingException e) {
			LOG.error("csv读取编码异常");
		} catch (IOException e) {
			LOG.error("csv读取IO异常", e);
		}
		return null;
	}

	/**
	 * csv写
	 *
	 * @param csvList
	 * @return
	 * @throws CsvException
	 */
	public static String csvWriter(List<Map<String, Object>> csvList) {
		String csvText = null;
		ByteArrayOutputStream stream = new ByteArrayOutputStream();
		CsvWriter writer = new CsvWriter(stream, ',', Charset.forName(ENCODING));
		if (csvList != null && csvList.size() > 0) {
			// 获取第一行map key,
			Map<String, Object> headMap = csvList.get(0);

			if (headMap != null && 0 <= headMap.size()) {
				// 提取cvs列
				Iterator<String> it = headMap.keySet().iterator();
				try {
					while (it.hasNext()) {
						writer.write(it.next());
					}
					writer.endRecord();
					boolean falg = false;
					for (Map<String, Object> csvMap : csvList) {
						if (falg) {
							writer.endRecord();
						}
						for (Entry<String, Object> map : csvMap.entrySet()) {
							String value = toStringWithOutNull(map.getValue());
							writer.write(value);
						}
						falg = true;
					}
					writer.close();
					csvText = stream.toString();
					stream.close();
					return csvText;
				} catch (IOException e) {
					LOG.warn("csv写入IO异常");
				}
			} else {
				LOG.warn("拆解cvs数据为空");
			}
		} else {
			LOG.warn("拆解cvs数据为空");
		}
		return null;
	}

}

 

• javacsv.jar (13.3 KB)
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