http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -%asHDQ{
} p* >z:=
for(int i=0;i<nEndPos.length-1;i++) QaWS%0go
{ 1JJsYX
nEndPos = nStartPos[i+1]; owAO&"C
} $dL..QH^K
nEndPos[nEndPos.length-1] = nFileLength; y* +y&
} Y}?8
} W2vL<
DR#" 3
5UEZpxnv
//启动子线程 ~7]V^tG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *8}b&4O~
for(int i=0;i<nStartPos.length;i++) t-\+t<;
{ Q0U~s\<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4V+bE$Wu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1h,iWHC
nStartPos,nEndPos,i); /5@YZ?|#2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l1+l@r\
fileSplitterFetch.start(); f"MID6
} +:MSY p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), - x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9[0iIT$q$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v] m/$X2
nEndPos = " + nFileLength); 1Viz`y)^
// fileSplitterFetch[nPos.length-1].start(); -,J<X\
{2\Y%Y'}*
TGCB=e
//等待子线程结束 f{sT*_at
//int count = 0; 2b"*~O;
//是否结束while循环 qE)FQeN
boolean breakWhile = false; q}{E![ZTu
) c@gRb~
tLE8+[ SU
while(!bStop) ? x)^f+:9|
{ q W(@p`
write_nPos(); M:+CW;||!
Utility.sleep(500); ,-UF5U
breakWhile = true; ,Z`}!%?
H/,KY/>i
eaw!5]huu
for(int i=0;i<nStartPos.length;i++) g3^s_*A
{ 8g#$Y2P
if(!fileSplitterFetch.bDownOver) LmrdVSs_
{ [&lK.?V)
breakWhile = false; il0K^i
break; O. * 0;5
} J%&LQ9
} z:QDWH
if(breakWhile) bZu'5+(@
break; 4Gu'WbJ
G%W9?4_K
RY-iFydPc
//count++; bC{4a_B
//if(count>4) WtM%(8Y[]
// siteStop(); iq&3S0
} ipSMmpB
+H-=`+,
(NJ{>@&
System.err.println("文件下载结束！"); LlTD =tJ0
} EGu%;[
catch(Exception e){e.printStackTrace ();} w\buQ6pR)
} (.J/Ql0Y
V DFgu
^C>kmo3J
//获得文件长度 !:(+#
public long getFileSize() T;w:^XW
{ [,=?e
int nFileLength = -1; }M07-qIX{
try{ #xIg(nG
URL url = new URL(siteInfoBean.getSSiteURL()); >M<3!?fW)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @6 he!wW
httpConnection.setRequestProperty("User-Agent","NetFox"); }\a#e^-xQ+
is.t,&H4P]
=EJ&=t
int responseCode=httpConnection.getResponseCode(); ]7HR U6$
if(responseCode>=400) pbMANZU[
{ (,Y[2_Zv
processErrorCode(responseCode); -&/?&{Q0
return -2; //-2 represent access is error (i&+=+"wn
} "x,lL
8ro`lX*F@2
JE.$]){
String sHeader; ~ #jQFyOh
H%_^Gy8f
q"d9C)Md
for(int i=1;;i++) vs@d)$N
{ ETDWG_H |
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fNNl1Vls
//Utility.log(in.readLine()); 6H#:rM
sHeader=httpConnection.getHeaderFieldKey(i); wE .H:q4&
if(sHeader!=null) Ev fvU:z
{ HE}0_x.
if(sHeader.equals("Content-Length")) mxlh\'b
{ Xaz "!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zIa={tU
break; x'|ty[87
} }k-V(
} axQ>~vWN/
else '6N)sqTR
break; bT:u|/I
} >8Oa(9n
} S_lGrk\j
catch(IOException e){e.printStackTrace ();} Fa("Gok[
catch(Exception e){e.printStackTrace ();} *yZ6"
Ww<Y]H$xZ<
Ah2@sp,z
Utility.log(nFileLength); a%#UF@I
5%-{r&
}7.A~h
return nFileLength; `d <`>
} Q{/z>-X\x
t=%zY~P
j0l{Mc5
//保存下载信息（文件指针位置） J6 ~Sr
private void write_nPos() tU4#7b:Y
{ aCZ0-X?c
try{ `>"#d ?,
output = new DataOutputStream(new FileOutputStream(tmpFile)); C[FHqo9M?H
output.writeInt(nStartPos.length); Ym'h vK
for(int i=0;i<nStartPos.length;i++) 8h] TI_
{ 1RAkqw<E
// output.writeLong(nPos); f+e"`80$*C
output.writeLong(fileSplitterFetch.nStartPos); 1W|jC
output.writeLong(fileSplitterFetch.nEndPos); d1~#@6CIz
} p6JTNxD
output.close(); g->*@%?<w>
} Nl\`xl6y]
catch(IOException e){e.printStackTrace ();} =,XCjiBeC
catch(Exception e){e.printStackTrace ();} [-(^>Y
} -%fQr5
TQR5V\{&%
CJ<nUIy'z
//读取保存的下载信息（文件指针位置） y|LHnNQ
private void read_nPos() /^=1]+_!
{ :Xw|v2z%3
try{ \M`qaFan5^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +wi=IrRr
int nCount = input.readInt(); zTng]Mvx
nStartPos = new long[nCount]; lZk z\
nEndPos = new long[nCount]; CE"/&I
for(int i=0;i<nStartPos.length;i++) .s{"NqRA
{ x`6MAZ
nStartPos = input.readLong(); LOUP
nEndPos = input.readLong(); BlJiHz!
} p4T$(]7
input.close(); Jm_)}dj3o
} '_v~+
catch(IOException e){e.printStackTrace ();} V%-hP~nyBx
catch(Exception e){e.printStackTrace ();} qda 2
} ebA:Sq:w
dIC\U
F5?S8=i
private void processErrorCode(int nErrorCode) :8b'HhjM
{ 6A"$9sj6
System.err.println("Error Code : " + nErrorCode); oU=vl!\J
} 'z} t= ?
0U=wGIO
gWj-@o\
//停止文件下载 O:?3B!wF
public void siteStop() ` o)KG,
{ 7xnj\9$m
bStop = true; ~"+"6zg
for(int i=0;i<nStartPos.length;i++) 1EU4/6!C
fileSplitterFetch.splitterStop(); Vb,VN?l
\ eHOHHAGW
TgkVd]4%
} 6]7csOE
} .SC*!,
//负责部分文件的抓取 5FZw (E
**FileSplitterFetch.java 'jt7H{M
*/ R+LKa Z
package NetFox; *'((_NZ>
'#6eUb
ox-m)z `7
import java.io.*; P~ObxY|
import java.net.*; aUw-P{zp%
"L3mW=!*
(?e%w}
public class FileSplitterFetch extends Thread { Ph3;;,v '
53t_#Yte
,`t+X=#
String sURL; //File URL x^1udK^re
long nStartPos; //File Snippet Start Position MblRdj6
long nEndPos; //File Snippet End Position a_Y<daRO
int nThreadID; //Thread's ID x2!R&q8U>
boolean bDownOver = false; //Downing is over K P]ar.
boolean bStop = false; //Stop identical U9oUY> 9
FileAccessI fileAccessI = null; //File Access interface {/QVs?d
<-I69`
G9:XEEN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =WTSaC
{ XIwJhsYZ'9
this.sURL = sURL; J,}h{-Xy`
this.nStartPos = nStart; m?w_ ]
this.nEndPos = nEnd; fJS:46
nThreadID = id; =x<N+vjXY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dlYpbw}W&<
} AE rPd)yk0
lDL&":t
`2Pa{g-.
public void run() BqNsW (+
{ v@qP &4Sp
while(nStartPos < nEndPos && !bStop) !!C/($
{ 8}|et~7!
U3_${
-8l<5g7
try{ Qx)b4~F?
URL url = new URL(sURL); V\`Z|'WIQD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W,4!"*+
httpConnection.setRequestProperty("User-Agent","NetFox"); vT?^#
String sProperty = "bytes="+nStartPos+"-"; ^_]ZZin
httpConnection.setRequestProperty("RANGE",sProperty); ;1(^H:7T
Utility.log(sProperty); ofB:7
NW1Jr/
o=Vs)8W
InputStream input = httpConnection.getInputStream(); UGAV"0
//logResponseHead(httpConnection); t6"%u3W8M
(%6fMVp
%7ngAIg
byte[] b = new byte[1024]; hTDK[4e
int nRead; {s8c@-'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >pF*unC;
{ zj7ta[<tr
nStartPos += fileAccessI.write(b,0,nRead); V,-we|"
//if(nThreadID == 1) x3y+=aj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3^/w`(-{@
} >V6t L;+
=UKxf
%jL^sA2;c+
Utility.log("Thread " + nThreadID + " is over!"); p}^G#h{
bDownOver = true; DhE-g<
//nPos = fileAccessI.write (b,0,nRead); n\+c3
} }a;xs};X;
catch(Exception e){e.printStackTrace ();} R1zt6oY
} $7q3[skH
} yXU.PSG*
nQc,^A)I
p#$/{;yy
//打印回应的头信息 4Fg2/O_3
public void logResponseHead(HttpURLConnection con) \]>YLyG
{ ~e}JqJ(97
for(int i=1;;i++) P)vD?)Q
{ A|ZT;\
String header=con.getHeaderFieldKey(i); JX&U?Z
if(header!=null) 3L&:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3m>YR-n$
Utility.log(header+" : "+con.getHeaderField(header)); 7${<u0((!
else 7DAP_C
break; w5>[hQR\
} .8YxEnXw)(
} RBQ8+^
sa'1hX^@
/"X_{3dq?
public void splitterStop() q;68tEupR
{ Xl4}S"a
bStop = true; LhL |ETrJ
} owIpn=8|Q
_V"0g=&Hc
<&\ng^Z$
} 0q5J)l:
c,@Vz 7c
]^ R':YE
/* z|>TkCW6
**FileAccess.java 9'*7 (j;
*//文件访问(定位，写) >M#@vIo?<6
package NetFox; Y:DopKRD
import java.io.*; JvO1tA]ij
H_?rbz}o
f\2IKpF2
public class FileAccessI implements Serializable{ 4kL6aSqT
72;'8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %RD\Sb4YV
RandomAccessFile oSavedFile; MG=E 6:
long nPos; w'TAM"D`
%M96m
s*PKr6X+
public FileAccessI() throws IOException <1*kXTN(
{ Tf3CyH!k
this("",0); =f~<*wQ
} aBC5?V*e%
CQ2vFg3+o
RZHfT0*jL
public FileAccessI(String sName,long nPos) throws IOException {.LJ(|(Mz
{ RL}?.'!
oSavedFile = new RandomAccessFile(sName,"rw"); 5len}){
this.nPos = nPos; )^(gwE
oSavedFile.seek(nPos); *tv&=
} K+~?yOQj
?;l@yx
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public synchronized int write(byte[] b,int nStart,int nLen) 2G8w&dtu
{ sTd@/>S?p
int n = -1; t~L4wr{B
try{ sRt7.fe
oSavedFile.write(b,nStart,nLen); 5qM$ahN3wH
n = nLen; @g#5d|U);
} <6(0ZO%,C!
catch(IOException e) Ts.2\-+3
{ q|ce7HnK
e.printStackTrace (); atZe`0
} >*EZZ\eU!
$q\"d?n
kEh\@x[
return n; 4ior
} b|_e):V|
M+:5gMB'
[3X\"x5@V
} }F]Z1('
XHA|v^
r:sa|+
/* S]@;`_?m{
**SiteInfoBean.java @K <Onh`
*/ /Qst :q
package NetFox; sV#%U%un
5$ik|e^:y
u4hn9**a1
public class SiteInfoBean { Mst%]@TG
}-tJ.3Zw
GFT@Pqq
private String sSiteURL; //Site's URL _S) K+C|@
private String sFilePath; //Saved File's Path frcX'M}%
private String sFileName; //Saved File's Name /%cDX:7X
private int nSplitter; //Count of Splited Downloading File *Hx*s_F
a]Pi2:S
%fg6',2
public SiteInfoBean() f:M^q ;
{//nSplitter的缺省值为5 , >WH)+a
//default value of nSplitter is 5 F`4W5~`
this("","","",5); x:-NTW -g
} :Fhk$?/r
s={>{,E
KH,f'`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #;8)UNc)}
{ _jX,1+M
sSiteURL= sURL; }36AeJ7L
sFilePath = sPath; 4Wgzp51Aq!
sFileName = sName; 9"^ib9M
this.nSplitter = nSpiltter; Z=8&`
,<Cl^ ^a,
-,/7u3
} >8/Otg+h
M.Q HE2
U LS>v
public String getSSiteURL() M_!]9#:K7
{ jvQ^Vh!mC
return sSiteURL; |]<#![!h#
} {*;8`+R&
K\ Wzh;
bYLYJ`hH<R
public void setSSiteURL(String value) x"Ll/E)\v]
{ N?m)u,6-l
sSiteURL = value; 9X*Z\-
} IiniaVuQ
<%.%q
:uAL(3pQ
public String getSFilePath() (^W}uDPCB
{ >h%>s4W
return sFilePath; U~=?I)Ni
} k(G6` dY
@Nb/n
<U$YJtEK
public void setSFilePath(String value) 1M`>;fjYa
{ 8G)~#;x1
sFilePath = value; I._ A
} }eSy]r[J
=( ZOn=IL
346 z`5
public String getSFileName() / ^)3V}
{ 5$+7Q$Gw
return sFileName; 7Wef[N\x
} o`,}b1lh
g<;pyvq|:
0fstEExw
public void setSFileName(String value) P8=|#yCi
{ `ZL^+h<b>M
sFileName = value; +E9G"Z65iP
} ue3 ].:
,W+=N"`a'
h];H]15&
public int getNSplitter() 9Pg6,[*u
{ a4uy}@9z
return nSplitter; 28v^j*=* \
} $G <r2lPy
[<i3l'V/[
5 `TMqrk
public void setNSplitter(int nCount) N'{Yhx u
{ ~I N g9|
nSplitter = nCount; `\:Ede
} &(<>} r
} <`-sS]=d}
l'<&H#A;'
a9&[Qv5-/
/* \roJf&O }
**Utility.java |}^u<S8X
*/ i5(qJ/u
package NetFox; n]vCvmt
[3=Y 9P:
,l!>+@
public class Utility { IJ+}
9Znc|<
b`%u}^B {
public Utility() <- sr&
{ Zl%)#=kO
V%[t'uh
fqbWD)L]
} 0X99D2c
jSBz),.XU}
//线程睡眠 _=x*yDPG}
public static void sleep(int nSecond) ]LsT
{ q/w5Dx|:
try{ `dF~'
Thread.sleep(nSecond); 6|Dtx5 "r
} 0-OKbw5%=b
catch(Exception e) QpzdlB44l
{ <gX({FA
e.printStackTrace (); <9H3d7%
} Q7pCF,;
} vD2(M1Q
:?EZ\WM7
//日志 Lm!]m\LRZD
public static void log(String sMsg) C!547(l[
{ Uth+4Aq
System.err.println(sMsg); $C=XSuPNK
} w)K547!00
8T.bT6
m%eCTpYo
public static void log(int sMsg) =ZoNkj/^,
{ 4T52vM
System.err.println(sMsg); )M.g<[=^
} )Dms9:
} KiMlbF.~V
XRM/d5
3 u=\d)eq
/* Qd~7OH4Lp
**TestMethod.java w&#[g9G%
*/ i\Yd_
package NetFox; $EIKi'!8
5mVO9Qj
YG?4DF
public class TestMethod { &B:L9^
[+5g 9tBJ
2T%sHp~qt
public TestMethod() e6J>qwD?
{ ///xx/weblogic60b2_win.exe kDJqT
try{ w&}<b%l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vx6lud0k}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nIlx?(=pu
SiteFileFetch fileFetch = new SiteFileFetch(bean); eo;MFd%;
fileFetch.start(); AD!w:jT9
} TqS s*as5
catch(Exception e){e.printStackTrace ();} xIc||o$
cJ?,\@uuP
FW2x
} (!m6>m2
:SwA) (1
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public static void main(String[] args) /J"fbBXwY
{ !:xE X~
new TestMethod(); ":sp0(`h
} AW_YlS
} z<P?p
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