dbf

Java library for fast reading/writing DBF-files.

Build from sources

For build project from sources you need to run gradlew script from the root directory:

git clone git@github.com:jamel/dbf.git
cd dbf
./gradlew clean build

dbf-reader

Maven artifact is available from maven central repository. Just add dependency in your pom.xml:

<dependency>
<groupId>org.jamel.dbf</groupId>
<artifactId>dbf-reader</artifactId>
<version>0.0.3</version>
</dependency>

Supported fields types

DBF field type	Returned as
character (C)	for reduce memory consumption and improve performance it returns as byte[]. If you need to get a String, use the appropriate constructor of String class.
date (D)	java.util.Date
float (F)	java.lang.Float
logical (L)	java.lang.Boolean
numeric (N)	java.lang.Number

How to use

1. Loading data from small dbf files into collection

In the next example we load data from streets.dbf mapping each row to objects of Street class:

publicclassLoadStreetsExample {
publicstaticvoidmain(String[] args) {
Filedbf = newFile("streets.dbf");
List<Street> streets = DbfProcessor.loadData(dbf, newDbfRowMapper<Street>() {
@OverridepublicStreetmapRow(Object[] row) {
// here we can change string encoding if it is neededStringname = newString(DbfUtils.trimLeftSpaces((byte[]) row[0]));
Numberzip = (Number) row[1];
DatecreatedAt = (Date) row[2];
returnnewStreet(name, zip.intValue(), createdAt);
}
});
System.out.println("Streets: " + streets);
}
}

2. Processing each row form dbf file

In the next example we calculate total sum and average price of data from products.dbf:

publicclassPricesCalcExampleV1 {
publicstaticvoidmain(String[] args) {
Filedbf = newFile("products.dbf");
TotalSumCalculatorcalc = newTotalSumCalculator();
DbfProcessor.processDbf(dbf, calc);
System.out.println("Total sum: " + calc.getTotalSum());
System.out.println("Average price: " + calc.getTotalSum() / calc.getRowsCount());
}
privatestaticclassTotalSumCalculatorimplementsDbfRowProcessor {
privatedoubletotalSum;
privateintrowsCount;
@OverridepublicvoidprocessRow(Object[] row) {
// assuming that there are prices in the 4th columntotalSum += ((Number) row[3]).doubleValue();
rowsCount++;
}
privatedoublegetTotalSum() {
returntotalSum;
}
privateintgetRowsCount() {
returnrowsCount;
}
}
}

3. Print general information of DBF-file

publicclassDbfInfo {
publicstaticvoidmain(String[] args) {
StringdbfInfo = DbfProcessor.readDbfInfo(newFile("altnames.dbf"))
System.out.println(dbfInfo);
}
}

Will print:

Created at: 13-7-15
Total records: 39906
Header length: 129
Columns:
# Name Type Length Decimal
---------------------------------------------
0 OLDCODE C 19 0
1 NEWCODE C 19 0
2 LEVEL C 1 0

4. Manually processing rows (low level API)

In the next example we again calculate total sum and average price of data from products.dbf. But this time we will manually create DbfReader and iterate throughout each row:

publicclassPricesCalcExampleV2 {
publicstaticvoidmain(String[] args) {
try (DbfReaderreader = newDbfReader(newFile("products.dbf"))) {
doubletotalSum = 0;
Object[] row;
while ((row = reader.nextRecord()) != null) {
// assuming that there are prices in the 4th columntotalSum += ((Number) row[3]).doubleValue();
}
System.out.println("Total sum: " + totalSum);
System.out.println("Average price: " + totalSum / reader.getHeader().getNumberOfRecords());
}
}
}

To get column values you can also use ResultSet-like API. The while loop from the last example can be rewritten like this:

DbfRowrow;
while ((row = reader.nextRow()) != null) {
totalSum += row.getDouble("Price");
}

5. Translate DBF to TXT file

If you have no tool for viewing DBF fields you could simply output all its content to txt file and use your favorite text editor.

publicclassDbf2Txt {
publicstaticvoidmain(String[] args) {
DbfProcessor.writeToTxtFile(
newFile("altnames.dbf"),
newFile("altnames.txt"),
Charset.forName("cp866"));
}
}

6. Read DBF records at a specified indices

To read one or more records at specific positions in the DBF without iterating through all records, you will have to use the DbfReader constructor which takes a File as an argument.

publicclassRandomRecordAccess {
publicstaticvoidmain(String[] args) {
try (DbfReaderreader = newDbfReader(newFile("multiple-records.dbf"))) {
// read the tenth record (the indices are zero-based)reader.seekToRecord(9);
Object[] record = reader.nextRecord();
// process the record ...// read the third recordreader.seekToRecord(2);
record = reader.nextRecord();
// process the record ...
}
}
}

dbf-writer

Dbf writing functionality currently is not available.