java将一组List<Map>对象以dbf文件方式导出
时间: 2024-02-10 14:10:41 浏览: 137
要将一组List<Map>对象以dbf文件方式导出,可以使用JavaDBF库。可以先下载JavaDBF库的jar包,并将其添加到项目中。然后可以使用以下代码将List<Map>对象导出为dbf文件:
```java
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.List;
import java.util.Map;
import com.linuxense.javadbf.*;
public class DBFWriter {
public static void main(String[] args) {
// List<Map>对象
List<Map<String, Object>> dataList = getDataList();
// dbf文件路径
String filePath = "example.dbf";
// 字段名数组
String[] fieldNames = getFieldNames(dataList);
// 字段类型数组
DBFField[] fields = getFields(dataList);
// 写入dbf文件
writeDBF(filePath, fieldNames, fields, dataList);
}
public static List<Map<String, Object>> getDataList() {
// 从数据库或其他数据源获取数据
// 省略...
return dataList;
}
public static String[] getFieldNames(List<Map<String, Object>> dataList) {
// 获取字段名数组
String[] fieldNames = null;
if (dataList != null && !dataList.isEmpty()) {
Map<String, Object> data = dataList.get(0);
fieldNames = new String[data.size()];
int i = 0;
for (String fieldName : data.keySet()) {
fieldNames[i++] = fieldName;
}
}
return fieldNames;
}
public static DBFField[] getFields(List<Map<String, Object>> dataList) {
// 获取字段类型数组
DBFField[] fields = null;
if (dataList != null && !dataList.isEmpty()) {
Map<String, Object> data = dataList.get(0);
fields = new DBFField[data.size()];
int i = 0;
for (String fieldName : data.keySet()) {
Object value = data.get(fieldName);
DBFField field = new DBFField();
field.setName(fieldName);
if (value instanceof Integer) {
field.setDataType(DBFField.FIELD_TYPE_N);
field.setFieldLength(10);
} else if (value instanceof Double) {
field.setDataType(DBFField.FIELD_TYPE_F);
field.setFieldLength(10);
field.setDecimalCount(2);
} else {
field.setDataType(DBFField.FIELD_TYPE_C);
field.setFieldLength(String.valueOf(value).getBytes().length);
}
fields[i++] = field;
}
}
return fields;
}
public static void writeDBF(String filePath, String[] fieldNames, DBFField[] fields, List<Map<String, Object>> dataList) {
DBFWriter writer = null;
try {
// 创建dbf文件
writer = new DBFWriter(new FileOutputStream(new File(filePath)), Charset.forName("GBK"));
// 设置字段名和类型
writer.setFields(fields);
// 写入每一条记录
for (Map<String, Object> data : dataList) {
Object[] rowValues = new Object[fieldNames.length];
for (int i = 0; i < fieldNames.length; i++) {
rowValues[i] = data.get(fieldNames[i]);
}
writer.addRecord(rowValues);
}
} catch (DBFException | IOException e) {
e.printStackTrace();
} finally {
if (writer != null) {
try {
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
```
其中,getDataList()方法可以从数据库或其他数据源获取数据,getFieldNames()方法获取字段名数组,getFields()方法获取字段类型数组。通过遍历每条记录,将数据写入dbf文件中。最后生成的dbf文件名为example.dbf,可以根据实际情况修改。
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