Use the FileInputStream class to read the content of any text file. Then, identify the characters present in the file and specify how many times each of them occurs.

Sure, I can help you with that!

To read the content of a text file using the FileInputStream class in Java, you need to follow these steps:

Step 1: Import the required classes:
```
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
```
Step 2: Create an instance of FileInputStream and open the file:
```
String filePath = "path_to_your_text_file";
try {
FileInputStream inputStream = new FileInputStream(filePath);
```
Step 3: Create a byte array to store the content of the file:
```
byte[] content = new byte[inputStream.available()];
```
Step 4: Read the content of the file using the read() method of FileInputStream:
```
inputStream.read(content);
```
Step 5: Close the file input stream:
```
inputStream.close();
```
Step 6: Convert the byte array to a string:
```
String fileContent = new String(content);
```
Now, to identify the characters present in the file and specify how many times each of them occurs, you can use a HashMap to store the characters as keys and their occurrence count as values.

Here's the code to accomplish that:

```
import java.util.HashMap;

HashMap charCountMap = new HashMap<>();

// Loop through each character in the file content
for (char c : fileContent.toCharArray()) {
if (charCountMap.containsKey(c)) {
// If the character is already in the map, increment its count
charCountMap.put(c, charCountMap.get(c) + 1);
} else {
// If the character is not in the map, add it with count 1
charCountMap.put(c, 1);
}
}

// Print the character count
for (char c : charCountMap.keySet()) {
System.out.println("'" + c + "'" + " occurs " + charCountMap.get(c) + " times.");
}
```

Answer: The code provided will read the content of the text file using the FileInputStream class and identify the characters present in the file along with the number of times each character occurs.