| Sample Reference - Schema Reference - Configuration Reference - API (Javadoc)
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| JasperReports - CSV Data Source Sample (version 4.0.1) | |
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| Main Features in This Sample | |
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| CSV Data Source |
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| CSV Query Executer |
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| Secondary Features | |
| Data Sources | |
| Query Executers | |
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 | CSV Data Source | Documented by Sanda Zaharia | |||||||
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| Description / Goal |
| How to fill a report using data from a CSV file. | ||||||
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| 1.2.0 | ||||||
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| Other Samples |
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CSV Data Sources
Report filling is one of the basic steps during the report generation. After the report compilation, significant report data are read from the report data source, or calculated from report expressions, and the generated JasperReport object is filled section by section. Data sources are very useful when data come as a set of structured records, either extracted from a relational database, or loaded from specific files. In order to become more familiar with data source objects please consult the Data Sources section. Sometimes data that users need to fill the report with is found in plain text files, in a certain format, such as the popular CSV (comma-separated value). JasperReports provides an implementation for such a data source, by wrapping the CSV data from a text file into a JRCsvDataSource. The CSV data source usually needs to read a file from disk, or at least from an input stream. CSV is a file format with very few formatting rules: data rows are separated by a record delimiter (text sequence) and fields inside each row are separated by a field delimiter (character). Fields containing delimiter characters can be placed inside quotes. If fields contain quotes themselves, these are duplicated (for example, "John ""Doe""" will be
displayed as John "Doe").
The most common delimiters for CSV files are:
setFieldDelimiter(char) and
setRecordDelimiter(String) of the JRCsvDataSource class.
There are two categories of CSV files:
setUseFirstRowAsHeader(true) method of the JRCsvDataSource.
If files belong to the second category (default), column names have to be provided separately, taking into account that the column names order should be the same as the column order in a data record. If this is not possible, the default naming convention is to use the COLUMN_ prefix followed by the zero-based column index.
For instance, if is known that a particular column is the third column in the record (index=2), then one could name the corresponding field "COLUMN_2" and use the column data without problems. Another problem when working with CSV files is related to data types. Handling data types for fields in CSV data sources is special since the CSV file format does not provide such information. This kind of matter is solved by trying to match each field in the data source to its corresponding report field type. For number and date/time fields, converting text values to java.lang.Number and java.util.Date values respectively
requires parsing using format objects. This is controlled by specifying the date and
number format objects to be used with the JRCsvDataSource instance by calling its
setDateFormat(DateFormat) and setNumberFormat(NumberFormat) methods
before passing it to the report-filling process.
CSV Data Source Example In our example data records are stored in the /data/CsvDataSource.txt file. Although the file extension is .txt,
it contains structured data according to the CSV rules:
"Dallas",47,"Janet Fuller","445 Upland Pl.","Trial" "Lyon",38,"Andrew Heiniger","347 College Av.","Active" "Dallas",43,"Susanne Smith","2 Upland Pl.","Active" "Berne",22,"Bill Ott","250 - 20th Ave.","Active" "Boston",32,"Michael Ott","339 College Av.","Trial" "Dallas",4,"Sylvia Ringer","365 College Av.","Active" "Boston",23,"Julia Heiniger","358 College Av.","Active" "Chicago",39,"Mary Karsen","202 College Av.","Active" "Dallas",40,"Susanne Miller","440 - 20th Ave.","Trial" "Berne",9,"James Schneider","277 Seventh Av.","Active" "Dallas",36,"John Steel","276 Upland Pl.","Suspended" "Chicago",35,"George Karsen","412 College Av.","Suspended" "Dallas",37,"Michael Clancy","19 Seventh Av.","Deleted" "Lyon",2,"Anne Miller","20 Upland Pl.","Active" "Dallas",0,"Laura Steel","429 Seventh Av.","Active" "Lyon",28,"Susanne White","74 - 20th Ave.","Deleted" "Paris",5,"Laura Miller","294 Seventh Av.","Active" "Lyon",17,"Laura Ott","443 Seventh Av.","Active" "New York",46,"Andrew May","172 Seventh Av.","Active" "New York",44,"Sylvia Ott","361 College Av.","Active" "Dallas",19,"Susanne Heiniger","86 - 20th Ave.","Active" "Chicago",11,"Julia White","412 Upland Pl.","Active" "Dallas",10,"Anne Fuller","135 Upland Pl.","Active" "New York",41,"Bill King","546 College Av.","Deleted" "Oslo",45,"Janet May","396 Seventh Av.","Active" "Paris",18,"Sylvia Fuller","158 - 20th Ave.","Trial" "San Francisco",48,"Robert White","549 Seventh Av.","Active" "Paris",25,"Sylvia Steel","269 College Av.","Suspended" "San Francisco",7,"James Peterson","231 Upland Pl.","Active" "Oslo",42,"Robert Ott","503 Seventh Av.","Trial"The file has no header row with column names. Column names are set independently, as shown in the getDataSource() method in the /src/CsvDataSourceApp.java file:
private static JRCsvDataSource getDataSource() throws JRException
{
String[] columnNames = new String[]{"city", "id", "name", "address", "state"};
JRCsvDataSource ds = new JRCsvDataSource(JRLoader.getLocationInputStream("data/CsvDataSource.txt"));
ds.setRecordDelimiter("\r\n");
ds.setColumnNames(columnNames);
return ds;
}
The five column names are: city, id, name, address and state,
in this particular order. Field names are identical to the column names defined here.
The JRCsvDataSource object prepared above is passed to the engine at fill time (see again the /src/CsvDataSourceApp.java file):
public void fill() throws JRException
{
long start = System.currentTimeMillis();
//Preparing parameters
Map parameters = new HashMap();
parameters.put("ReportTitle", "Address Report");
parameters.put("DataFile", "CsvDataSource.txt - CSV data source");
Set states = new HashSet();
states.add("Active");
states.add("Trial");
parameters.put("IncludedStates", states);
JasperFillManager.fillReportToFile("build/reports/CsvDataSourceReport.jasper", parameters, getDataSource());
System.err.println("Filling time : " + (System.currentTimeMillis() - start));
}
The IncludedStates parameter defined above is used for data filtering. Only records with Active
or Trial states will be taken into account:
<parameter name="IncludedStates" class="java.util.Set"/>
Running the Sample Running the sample requires the Apache Ant library. Make sure that ant is already installed on your system (version 1.5 or later).
In a command prompt/terminal window set the current folder to demo/samples/csvdatasource within the JasperReports source project and run the > ant test view command.
It will generate all supported document types containing the sample report in the demo/samples/csvdatasource/build/reports directory.
Then the report will open in the JasperReports internal viewer. |
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| CSV Query Executer | Documented by | |||||||
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| Description / Goal |
| How to fill a report using the CSV query executer. | ||||||
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| Since |
| 4.0.0 | ||||||
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| Other Samples |
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