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)); [niFJIsc
} R3_OCM_*
for(int i=0;i<nEndPos.length-1;i++) [.xY>\e
{ qm><}N7f
nEndPos = nStartPos[i+1]; Lg!E
} 3\j`g
nEndPos[nEndPos.length-1] = nFileLength; :FS5BT$=
} ?<3 d Fb
} 9AhA"+?
m=@xZw<
"Ux(nt
//启动子线程 i@?|vu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n5UUoBv
for(int i=0;i<nStartPos.length;i++) /fb}]e]N
{ iTAj${ >
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z/4<x?}+hE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Uvm.|p_V
nStartPos,nEndPos,i); I@Hx LEGj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iu8Q &Us0P
fileSplitterFetch.start(); 96~y\X@x
} LJPJENtFIs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T})q/oUqK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J~WT;s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +%\Ci!%b
nEndPos = " + nFileLength); CqC )H7A
// fileSplitterFetch[nPos.length-1].start(); L%Zr3Ct
K)>F03=uE
K<5yjG8&
//等待子线程结束 X/:V{2
//int count = 0; ;.sYE/ZVi
//是否结束while循环 ^_@[1'^
boolean breakWhile = false; ~8nR3ki
{Dl@/fz
z;oia!9z
while(!bStop) TxF^zx\
{ "i#g [x
write_nPos(); j3-o}6
Utility.sleep(500); ed',\+.uB
breakWhile = true; PZqp;!:xz
~$K{E[^<
DL4`j>2Ov
for(int i=0;i<nStartPos.length;i++) BuRsz6n
{ rbdrs
if(!fileSplitterFetch.bDownOver) @H#Fzoo.
{ ,}'8. f
breakWhile = false; K2x2Y=
break; QK6_dIvDz
} Izu____
} 4w ,&#L
if(breakWhile) w%qnH e9
break; O-V]I0
Yh1nXkA!V
Q<AOc\oO
//count++; [XI:Yf
//if(count>4) P!f0&W
// siteStop(); SzB<PP2
} 'J} ?'{.
0`7yPq*
AA^K/y
System.err.println("文件下载结束！"); 9;6)b0=$
} 0M;El2 P$
catch(Exception e){e.printStackTrace ();} QnS^ G{
} ._tEDY/1m
;303fS
cSYCMQ1ro
//获得文件长度 2_u+&7
public long getFileSize() Z ;rM@x
{ H*k\C
int nFileLength = -1; KH?6O%d
try{ }[z7V
URL url = new URL(siteInfoBean.getSSiteURL()); sz270k%[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U=KUx
httpConnection.setRequestProperty("User-Agent","NetFox"); PUO7Z2
`=hCS0F
*GXPN0^Qjo
int responseCode=httpConnection.getResponseCode(); 9F3,
if(responseCode>=400) x1g-@{8]j
{ -j<E_!t
processErrorCode(responseCode); >e/>@ J*
return -2; //-2 represent access is error vd#)+
} ;6hoG(3 +
#A4WFZ
HRE?uBkjf
String sHeader; wX2U
"!Ph
Ewkx4,`Ff
for(int i=1;;i++) /d|:
{ i9Bh<j>:J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5SUO`4L
//Utility.log(in.readLine()); '6NrL;
sHeader=httpConnection.getHeaderFieldKey(i); RICm$,
if(sHeader!=null) R[\1Kk(Zo
{ ylczM^@
if(sHeader.equals("Content-Length")) s'N<
{ ;Ngk"5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WxYEu+_
break; YJ,"@n_
} iNkN'("
} ~ e?af
else 'L3MHTM>[
break; \36 G``e
} nU{Qi;0
} ?0dmw?i
catch(IOException e){e.printStackTrace ();} }[|9vF"g.y
catch(Exception e){e.printStackTrace ();} [g}#R#Y)
vde!k_,wZ
^"I@ 8k
Utility.log(nFileLength); w+')wyB
hC"'cUrcN
bR~Xog
return nFileLength; TDk[,4
} 8 0nu^_
Zl9
d`V.i6u
//保存下载信息（文件指针位置） MXl_{8
private void write_nPos() fCNQUK{Gs5
{ e}{#VB<
try{ 9C?SEbC
output = new DataOutputStream(new FileOutputStream(tmpFile)); RrBG=V
output.writeInt(nStartPos.length); 4Dzg r,V
for(int i=0;i<nStartPos.length;i++) "[]oWPOj
{ {ly<%Q7j
// output.writeLong(nPos); $s1/Rmw
output.writeLong(fileSplitterFetch.nStartPos); Q}\\0ajS)
output.writeLong(fileSplitterFetch.nEndPos); Zbre5&aU
} `'iO+/;GY
output.close(); ;lE=7[UJ3X
} #E Bdg
catch(IOException e){e.printStackTrace ();} u!~kmIa4
catch(Exception e){e.printStackTrace ();} rd%uc~/
} Z>R@
F|+B8&-v
_nz_.w0H9
//读取保存的下载信息（文件指针位置） ,<P"\W
private void read_nPos() Q'^'G>MBJ
{ (FGy"o%TP'
try{ (p#c p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &Hf%Va[B
int nCount = input.readInt(); $A5O>
nStartPos = new long[nCount]; Kp7)my
nEndPos = new long[nCount]; o@PvA1
for(int i=0;i<nStartPos.length;i++) !!ZGNZ_
{ a"Iu!$&N
nStartPos = input.readLong(); oVP,ar0G
nEndPos = input.readLong(); T[e+iv<8j
} sF :pwI5^
input.close(); v~AshmP
} k t!@}QP
catch(IOException e){e.printStackTrace ();} I_Lm[
catch(Exception e){e.printStackTrace ();} :/SGB3gb1t
} X7K{P_5l
I8@leT\9M
'-f` 5X
private void processErrorCode(int nErrorCode) Ux^ue9
{ {I0!q"sF
System.err.println("Error Code : " + nErrorCode); &.2%p
} J80&npsO
#+Bz$CO
_?felxG[
//停止文件下载 %LHt{:9.
public void siteStop() )R<93`q
{ gGCr~.5
bStop = true; Rq2bj_j
for(int i=0;i<nStartPos.length;i++) .#tA .%
fileSplitterFetch.splitterStop(); :0%[u(
dj] O
T:%0i8p
} D` cy.},L
} 5IzCQqOPgX
//负责部分文件的抓取 8f~*T
**FileSplitterFetch.java !W&|kvT^
*/ U74L:&yLI
package NetFox; 9_svtO]P
]YZ_kc^(V;
F&7Z(
import java.io.*; vnbY^ASdw
import java.net.*; &a\w+
&'/PEOu&}G
?G9DSk?6%Z
public class FileSplitterFetch extends Thread { K0'p*[yO/j
V1nqEdhk
&q-P O
String sURL; //File URL ,=@WE>ip
long nStartPos; //File Snippet Start Position A$\/D2S7!
long nEndPos; //File Snippet End Position e :ub]1I=
int nThreadID; //Thread's ID 1=>b\"P#E
boolean bDownOver = false; //Downing is over k'F*uS
boolean bStop = false; //Stop identical \(^]R,~*!b
FileAccessI fileAccessI = null; //File Access interface VJ&-Z |
9.~_swkv
SMB&sl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0RCp
{ Pu!C,7vUQ
this.sURL = sURL; &Nr+-$
this.nStartPos = nStart; 1p/_U?H:|
this.nEndPos = nEnd; d"3x11|
nThreadID = id; $*XTX?,'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^^uY)AL
} 6P(jc
) .V,zmI
$_HyE%F#
public void run() 3S>rc0]6
{ 0#Q]>V@rO4
while(nStartPos < nEndPos && !bStop) $LU|wW
{ Mz) r'
n sN n>{
a|dgK+[
try{ VyIJ)F.c
URL url = new URL(sURL); y{P~!Yn|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8<6@O
httpConnection.setRequestProperty("User-Agent","NetFox"); d[;&2Jz*
String sProperty = "bytes="+nStartPos+"-"; %[L/JJbP&Z
httpConnection.setRequestProperty("RANGE",sProperty); ??hKsjNAm0
Utility.log(sProperty); I&1.}{G>F
i(# Fjp
{~\:4
InputStream input = httpConnection.getInputStream(); r|bGn#^
//logResponseHead(httpConnection); Ka)aBU9
1csbuR?
o {q8An)
byte[] b = new byte[1024]; H-m).^
int nRead; JNvgUb'U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B/~ubw
{ Gh3f^PWnc
nStartPos += fileAccessI.write(b,0,nRead); %vG;'_gMB
//if(nThreadID == 1) YD~(l-?"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^h`rA"F\
} Hp(41Eb,
}LWrtmc
:.-KM7tDI1
Utility.log("Thread " + nThreadID + " is over!"); ^s=F<_{
bDownOver = true; yRhD<*
//nPos = fileAccessI.write (b,0,nRead); 5ry[Lgg
} {pRa%DF
catch(Exception e){e.printStackTrace ();} c~\^C_
} 4q@[k:'
} _39VL
_$}@hD*R~
-s91/|n
//打印回应的头信息 ^d9o \
public void logResponseHead(HttpURLConnection con) ^@'zQa
{ 8-O:e
for(int i=1;;i++) *TxR2pC}
{ 0J5$ Yw1'F
String header=con.getHeaderFieldKey(i); M|.ykA<D
if(header!=null) %~Ymb&ugg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Cq\{\!6[
Utility.log(header+" : "+con.getHeaderField(header)); VdL }$CX$
else Kt"4<'
break; Us>n`Lj@
} ' #t1e]
} JQ]MkP
[#:yOZt
z5f3T D6,
public void splitterStop() ; ?,'jI*1
{ yzGBGC
bStop = true; .+ic6
} +sd':vE
U!lWP#m
R~dWblv
} EiA_9%<
ar`}+2Qh0
2m&?t_W
/* /w*HxtwFmD
**FileAccess.java eX^ F^(
*//文件访问(定位，写) p,)pz_M
package NetFox; Ao *{#z
import java.io.*; o107.s
$fW8S8
ab_EH}j1\q
public class FileAccessI implements Serializable{ vb\R~%@T,
f(-3d*g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d\ Xijy
RandomAccessFile oSavedFile; dpcv'cRfw
long nPos; r?Pk}Q
$! UEpQ
p1\EC#Q
public FileAccessI() throws IOException 8U-<Q>
{ "Z a}p|Ct
this("",0); 5PKdMEK|q
} E{B40E~4
=XUt?5
myZ8LQ&
public FileAccessI(String sName,long nPos) throws IOException z-kB!~r
{ !wjD6NK
oSavedFile = new RandomAccessFile(sName,"rw"); !R$t>X
this.nPos = nPos; 3.04Toq!
oSavedFile.seek(nPos); [sG!|@r
} kx[h41|n
cvnRd.&
^0"[l {
public synchronized int write(byte[] b,int nStart,int nLen) /gLi(Uw
{ Zu^J X/um
int n = -1; /}-LaiS
try{ &?SU3@3|
oSavedFile.write(b,nStart,nLen); !2=eau^p
n = nLen; ^Pc&`1Ap
} )G$0:-J-
catch(IOException e) M7AUY#)
{ ::k/hP9.^
e.printStackTrace (); sHMZ'9b
} H|B4.z
0hju@&Aa
AkV8}>G?#A
return n; Y/n],(t)
} '$be+Z32
nnnq6Z}
d-$/C| J
} ->U9u lTC
:]IYw!_-p
_i1x\Z~ N
/* kT{d pGU9
**SiteInfoBean.java f!##R-A
*/ 8>V)SAI'
package NetFox; _WHGd&u
g h&,U`
:+}Eo9
public class SiteInfoBean { Jg%jmI;Y
kT4Tb%7KM
;PX>] r5U0
private String sSiteURL; //Site's URL g=n /w
private String sFilePath; //Saved File's Path =xsTVT;sj
private String sFileName; //Saved File's Name 8u#2M8.5E
private int nSplitter; //Count of Splited Downloading File [e`6gGO
THDyb9_g
EEO)b_(
public SiteInfoBean() U>kL|X3 V
{//nSplitter的缺省值为5 *`wgqin
//default value of nSplitter is 5 A;C)#Q/
this("","","",5); G8!* &vR/
} HFrwf{J
JG!@(lr
ir3EA'_>N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <Yy|.=6 D
{ yj C@
sSiteURL= sURL; :/'oh]T|
sFilePath = sPath; +HNM$yp
sFileName = sName; $/;;}|hqi
this.nSplitter = nSpiltter; InR/g@n+D1
"E )0)A3=
!%%(o%bi~
} 'z3I*[!
^N:bT;;$nZ
Q!G^CG
public String getSSiteURL() 6'1m3<G_
{ XhG3Of-6
return sSiteURL; 16R0#Q/{+*
} V'&`JZK6
ww$Ec
ua>YI
public void setSSiteURL(String value) _G=k^f_
{ "Z*u2_ H
sSiteURL = value; /p_#8}Uh
} HH94?&
o+^5W
%6@->c{
public String getSFilePath() JP*VR=0k?
{ dw]jF=u
return sFilePath; %T'<vw0
} 6E@qZvQ
&a bR}J[
}IGoPCV|
public void setSFilePath(String value) j$Z:S~*
{ `5CuH
sFilePath = value; Tg~SGAc
} |#?:KvU97E
$c<NEt_\
U[t/40W}P
public String getSFileName() xb~8uD5
{ @j|=M7B
return sFileName; c 1o8
} 6@; P
#:LI,t
d| OEZx
public void setSFileName(String value) o6T'U#7P
{ @J UCXm
sFileName = value; #cy;((zuB
} NANgV~Y&
k~=_]sLn
*'jI>^o
public int getNSplitter() 5VR=D\j
{ qz6@'1
return nSplitter; K#!c<Li#
} 8*Ke;X~N
|g,99YIv>
Js}1_K
public void setNSplitter(int nCount) ni`uO<\U
{ {ZIEIXWb2
nSplitter = nCount; RJk42;]
} nBJ'ak
} Uon^z?0A
?0J&U4
c$#7Kp4
/* -#<AbT
**Utility.java Cu&y',ee~
*/ zVyMmw\
package NetFox; !}PZCbDhL
BMs?+
w9]HJ3qi
public class Utility { 2U.'5uA"L
;G|#i?JJ
yeqHeZ
public Utility() *BFG{P
{ PEDV9u[A
>PmnR>x-rj
S";c7s
} xh|<`>5
&UfP8GE9
//线程睡眠 RBOg;EJ
public static void sleep(int nSecond) iV2v<ap.n
{ }NpN<C+
try{ wlsq[xP
Thread.sleep(nSecond); 0 n}2D7
} ,y}@I"
catch(Exception e) ^ZPynduR
{ It:,8
e.printStackTrace (); 6%L#FSI
} !j%MN{#a
} 51-@4E2:l:
{j[a'Gb
//日志 JBk >|q"
public static void log(String sMsg) ^aR^M\38
{ []b= xRJM
System.err.println(sMsg); SQs+4YJ
} n4InZ!)
p!>DA?vF
x|`BF%e/v
public static void log(int sMsg) t0.71(
{ _Nacqa
System.err.println(sMsg); Lq2ZgKd!
} >0E3Em<(}l
} Nbb2wr9A
8@,8j!$8G
s((c@)M
/* GUn$IPOM
**TestMethod.java B]u!BBjC
*/ #Oi{7~
package NetFox; w8}jmpnI
)m_q2xV
|'qvq/#^
public class TestMethod { /(8"9Sfm
:Lu 9w0>f
YHzP/&0
public TestMethod() L(o#)I>j
{ ///xx/weblogic60b2_win.exe Ubm]V{7
try{ COA*Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9";qR,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )~-r&Q5d
SiteFileFetch fileFetch = new SiteFileFetch(bean); O-&^;]ieJ
fileFetch.start(); %f5c,}
} @Y !Jm
catch(Exception e){e.printStackTrace ();} L<k(stx~
46U*70
RQYD#4|
} o1R:1!"2
c2Wp 8l
~s*kuj'%+
public static void main(String[] args) &}r-C97
{ qs{wrem
new TestMethod(); >|aVGY
} J p)I9k,Ez
} *i>hFNLdOM
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