String splicing with custom function

1.1 Expected effect

You can use the StringCat function to splice strings in BI. For example, splice the "area" and "hierarchical market" under the "AC-sales" into one field, as shown in the following figure:

Note: the functions and fields in the formula box need to be selected by clicking the selection area on the left, and cannot be entered manually.

1.2 Implementation ideas

"AbstractFunction" implements the "Function" interface, so StringCat can directly inherit the "AbstractFunction" class.

When using the function StringCat (Para, Para, Para,...), obtain the class StringCat that operates the function according to the function name, pass the parameters into the args object array in the class, and execute the run function of the class. In the run function, the incoming parameters are connected in the form of strings. And returns the resulting string.

Note: please refer to file: "User defined function introduction" for more details of user defined function definition rules and precautions.

1.3 Function introduction

Function StringCat ：the function is to connect all parameters in the form of string.

StringCat's usage rules are StringCat(Para,Para,Para…….), where "Para" is an unlimited number of parameters of the function.

2.1 Write Java files

Write StringCat.java. The function code is as follows.

package com.fr.function;
import com.fr.script.AbstractFunction;
public class StringCat extends AbstractFunction {
public Object run(Object[] args) {
String result = "";
Object para;
for (int i = 0; i < args.length; i++) {
para = args[i];
result += para.toString();
}
return result;
}
}

2.2 Compiling class files

2.2.1 Compilation environment preparation

For more details, see file: "Compiling Java programs".

2.2.2 Generate class file

Compile StringCat.java, generate the class StringCat.class.

2.2.3 Import class file

Put the compiled StringCat.classinto finebi installation directory%FineBI%\webapps\webroot\WEB-INF\classes\com\fr\function, as shown in the following figure:

Note: if there is no corresponding directory under WEB-INF, you can create a new directory.

2.3 Use custom functions

After  restarting FineBI, it can be used directly. The method is the same as the built-in function.

For example, in adding "calculation indicators", you can see the previously customized function StringCat below other functions. Click this function to add it to the formula, as shown in the following figure:

Splice the "area" and "hierarchical market" under the "AC-sales" into one field, and enter the formula: StringCat(${area}," ",${hierarchical Market}), as shown in the following figure:

Note: the functions and fields in the formula box need to be selected by clicking the selection area on the left, and cannot be entered manually.

2.4 View the effects

See Section 1.1 of this file for details.

Refer to section 2.1, 2.2.1, 2.2.2 of this file to compile and generate the StringCat.class.

3.1 Import class file

Store the StringCat.class file in the %FineBI%\webapps\webroot\WEB-INF\classes\com\fr\function , as shown in the following figure:

The file can be stored anywhere in the FineBI project directory, but it should correspond to the location under package in the java file. For example, this example is:

package com.fr.function;

Therefore, you need to store the class file under the %FineBI%\webapps\webroot\WEB-INF\classes\com\fr\function file. If the codes are:

package com;

Then you can store the file under the %FineBI%\webapps\webroot\WEB-INF\classes\com .

3.2 Register custom functions

After generating the class of this function, you need to register in FineReport designer before you can use this function.

See the file "FineReport designer remotely connect to FineBI project", open "Server" → "Function Manager", add a function and name it as "StringCat", select the defined StringCat.class and save it, as shown in the following figure:

3.3 Use custom functions

After  restarting FineBI, it can be used directly. The use method is the same as the built-in function.

Note: if the remote connection is cancelled after registration, the user-defined function can still be used.

3.4 View the effect

See more details in section 1.1.