我正在尝试将Object
编组为csv String
。我创建了一种可以将任何对象转换为csv String
的方法,但是我不断收到异常:
java.lang.NoSuchMethodError: org.codehaus.jackson.map.ObjectMapper.writer(Lorg/codehaus/jackson/FormatSchema;)Lorg/codehaus/jackson/map/ObjectWriter;
元帅法:
public static final synchronized String marshal(final Object object, final CsvSchema csvSchema) throws IOException {
String CSV_FILTER_NAME = "csvFilter";
HashSet<String> columnNames = new HashSet<>();
for (CsvSchema.Column column : csvSchema) {
columnNames.add(column.getName());
}
SimpleBeanPropertyFilter csvReponseFilter = new SimpleBeanPropertyFilter.FilterExceptFilter(columnNames);
FilterProvider filterProvider = new SimpleFilterProvider().addFilter(CSV_FILTER_NAME, csvReponseFilter);
CsvMapper csvMapper = new CsvMapper();
csvMapper.setFilters(filterProvider);
csvMapper.setAnnotationIntrospector(new JacksonAnnotationIntrospector() {
@Override
public Object findFilterId(AnnotatedClass annotatedClass) {
return CSV_FILTER_NAME;
}
});
ObjectWriter objectWriter = csvMapper.writer(csvSchema);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
objectWriter.writeValue(byteArrayOutputStream, csvSchema);
return new String(byteArrayOutputStream.toByteArray(), "UTF-8");
}
主要方法:
public static void main(String args[]) {
CsvSchema csvSchema = CsvSchema.builder()
.addColumn("name")
.addColumn("age")
.addColumn("height")
.addColumn("weight")
.setUseHeader(true)
.build()
.withLineSeparator("\n");
Person person = new Person("Tim", "32", "184", "100");
try {
System.out.println(CsvUtilities.marshal(person, csvSchema));
} catch (IOException ex) {
Logger.getLogger(CsvUtilities.class.getName()).log(Level.SEVERE, null, ex);
}
}
是什么导致此异常?
编辑这是我所有的进口:
import com.fasterxml.jackson.dataformat.csv.CsvMapper;
import com.fasterxml.jackson.dataformat.csv.CsvSchema;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.List;
import java.util.logging.Logger;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.codehaus.jackson.map.ObjectWriter;
import org.codehaus.jackson.map.introspect.AnnotatedClass;
import org.codehaus.jackson.map.introspect.JacksonAnnotationIntrospector;
import org.codehaus.jackson.map.ser.FilterProvider;
import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
最佳答案
在课程路径中查看罐子。可能有两种或不同版本的杰克逊罐子没有此方法。可能是Class loader加载了较旧的版本。
还检查您已添加到项目中的依赖项。