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)); X_!mZ\H7
} /@#)j( eY/
for(int i=0;i<nEndPos.length-1;i++) %\b5)p
{ 6AQ;P
nEndPos = nStartPos[i+1]; #-lk=>
} r LfS9H
nEndPos[nEndPos.length-1] = nFileLength; }Xc|Z.6
} CKBi-q FH
} M.OWw#?p:_
5h{Hf]A
LnJ7i"Q
//启动子线程 It_yh #s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t*}<v@,
for(int i=0;i<nStartPos.length;i++) 8=nm`7(]
{ }p- %~Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JAiV7v4&R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :m$%D]WY
nStartPos,nEndPos,i); ^d=Z/d[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {Zseu$c
fileSplitterFetch.start(); _^'k_a
} ;%k%AXw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >8AtT=}w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8dZH&G@;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zIAMM
nEndPos = " + nFileLength); 15eHddd
// fileSplitterFetch[nPos.length-1].start(); rLKDeB
WG}QLcP
@pS[_!EqYz
//等待子线程结束 LB{a&I LG
//int count = 0; LAwS8t',
//是否结束while循环 e5XikLu
boolean breakWhile = false; sN?:9J8
YJL=|v
11-uJVO~*
while(!bStop) ^y6CV4T+
{ h`GV[Oo:
write_nPos(); *{Z!m@?
Utility.sleep(500); Y zvtxX*
breakWhile = true; 87>Qw,r
Bpp9I;)c
QV 'y6m\
for(int i=0;i<nStartPos.length;i++) w6yeX<!ll
{ hWW<]qzA,
if(!fileSplitterFetch.bDownOver) 'Qfy+_0
{ y(zU:.
breakWhile = false; AdYQhF##
break; |$w-}$jq5
} HZ}'W<N
} <?7~,#AK
if(breakWhile) X'F$K!o*,:
break; Uh8ieb
uJ y@
$Yxy(7d7w
//count++; d!X?R}
//if(count>4) 5(|ud)v
// siteStop(); HWU{521
} bbM !<&F
mT9\%5d3
68>zO%
System.err.println("文件下载结束！"); t&uHn5
} lKwcT!Q4
catch(Exception e){e.printStackTrace ();} >k jJq]A2
} W P&zF$
"|%fAE
E4.IS=4S
//获得文件长度 +]zP $5_e
public long getFileSize() CKur$$B
{ g!8lW
int nFileLength = -1; yLX#: nm
try{ .WPqK>79|
URL url = new URL(siteInfoBean.getSSiteURL()); vJ' 93h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LYFvzw>M
httpConnection.setRequestProperty("User-Agent","NetFox"); -XyuA:pxx
\* #4
.KSGma6]
int responseCode=httpConnection.getResponseCode(); ?!66yn
if(responseCode>=400) ou-;k }
{ /W>"G1)
processErrorCode(responseCode); Dw[Q,SE
return -2; //-2 represent access is error zVa+5\Q
} {XCrjO|
?yb{DZ46
5`DH\VD.j
String sHeader; zK92:+^C
BkeP?X
m>!#}EJ|
for(int i=1;;i++) el%Qxak`"
{ sJlKN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BYf"l8^,
//Utility.log(in.readLine()); 7EXmmB~>,
sHeader=httpConnection.getHeaderFieldKey(i); !;a<E:
if(sHeader!=null) i5"q1dRQ
{ iD`XD\.?
if(sHeader.equals("Content-Length")) c%!wKoD
{ |{K:.x#^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8(;i~f:bCW
break; 9 JtG&^*
} 3"n8B6
} "lZ<bG
else jFv<]D%A[
break; dp70sA!JF
} }+J@;:
} k#&SWp=
catch(IOException e){e.printStackTrace ();} .#J3UZ
catch(Exception e){e.printStackTrace ();} co80M;4
YLo$n
M[{:o/]<
Utility.log(nFileLength); 1aG}-:$t'
'1 $({{R
]l'ki8
return nFileLength; {@%(0d{n}
} -`UlntEdZ:
s`YuH <8
>xKRU5
//保存下载信息（文件指针位置） t@n (a
private void write_nPos() 0Kk*~gR?
{ pH[lj8S
try{ h)vTu%J:
output = new DataOutputStream(new FileOutputStream(tmpFile)); Se`N5hQ
output.writeInt(nStartPos.length); 8|GpfW3p2
for(int i=0;i<nStartPos.length;i++) Qg!*=<b
{ zY+Et.lg]^
// output.writeLong(nPos); 3(&F.&C$$
output.writeLong(fileSplitterFetch.nStartPos); M(uB ;Te
output.writeLong(fileSplitterFetch.nEndPos); 9a%@j ]
} $O8V!R*
output.close(); v!xrUyN~m
} ~S!kn1&O
catch(IOException e){e.printStackTrace ();} &:*+p-!2<
catch(Exception e){e.printStackTrace ();} %#a%Luq
} GcCs}(eo
_'U?!
xk8p,>/
//读取保存的下载信息（文件指针位置） dCTpO
private void read_nPos() w"iZn
{ uLljM{I
try{ OvG0UXRU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u_8 22Z
int nCount = input.readInt(); NGUGN~p
nStartPos = new long[nCount]; AHY)#|/)
nEndPos = new long[nCount]; q?4uH;h:^G
for(int i=0;i<nStartPos.length;i++) %ko 8P
{ :<8V2
nStartPos = input.readLong(); 8v 1%H8
nEndPos = input.readLong(); HPKyAcS\
} ;i:wY&
input.close(); ~[q:y|3b
} );DIrA
catch(IOException e){e.printStackTrace ();} ^)l@7XxD
catch(Exception e){e.printStackTrace ();} @|Bp'`j%J
} eE%yo3
_|:bac8pL
H>iZVE
private void processErrorCode(int nErrorCode) nV*sdSt
{ ,z)NKt#
System.err.println("Error Code : " + nErrorCode); ss8v4@C
} #!,`EU
86F+N_>Z
12xP)*:$
//停止文件下载 >8O=^7
public void siteStop() kw ^ Sbxm
{ em!R9J.
bStop = true; _Pi:TxY
for(int i=0;i<nStartPos.length;i++) N|2
fileSplitterFetch.splitterStop(); %esZ}U
(1j$*?iGA
L"6/"L
} "mDrJTWa
} t~K!["g
//负责部分文件的抓取 D D;+& fe
**FileSplitterFetch.java f+Li'?
*/ C*e[CP@u
package NetFox; +STzG/9#
72vGfT2HtZ
`1<3Hu_
import java.io.*; ,ri--<
import java.net.*; -L?% o_
8z8SwWS?
4$GRCq5N;
public class FileSplitterFetch extends Thread { A;a(n\Sy
/~cL L
Sc3M#qm_
String sURL; //File URL E(+wl
long nStartPos; //File Snippet Start Position ,<r3Z$G
long nEndPos; //File Snippet End Position "sX?wTag
int nThreadID; //Thread's ID SJ7=<y}[d
boolean bDownOver = false; //Downing is over <?Izfl6
boolean bStop = false; //Stop identical ={@ @`yP^$
FileAccessI fileAccessI = null; //File Access interface 6Ok=q:;
|P0L,R
Y6?mY!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SSbK[aR
{ T4Gw\Z%
this.sURL = sURL; xWe1F2nY
this.nStartPos = nStart; vP)~j1
this.nEndPos = nEnd; E(kb!Rz
nThreadID = id; p<fgUVR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7"NJraQ6
} )K%O/H
Fd,+(i D
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public void run() =&:f+!1$
{ B%:9P
while(nStartPos < nEndPos && !bStop) T1!Gr!=
{ 3=|2Gs?ut
y&=19A#
"M0l;
try{ UMi`u6#
URL url = new URL(sURL); gIM'bA<~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a:^Gr%
httpConnection.setRequestProperty("User-Agent","NetFox"); UQ?OD~7
String sProperty = "bytes="+nStartPos+"-"; [67E5rk-
httpConnection.setRequestProperty("RANGE",sProperty); 6 %k+0\d
Utility.log(sProperty); 8Y~=\(5>
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S}Y|s]6
InputStream input = httpConnection.getInputStream(); ^zPEAXm
//logResponseHead(httpConnection); (yAvDyJOn
#Q7x:,f
"~2#!bK7
byte[] b = new byte[1024]; 5~%,u2
int nRead; 6?.pKFBZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u#@{%kPW
{ 5h=TV
nStartPos += fileAccessI.write(b,0,nRead); =<zSF\Zr_
//if(nThreadID == 1) C"^hMsU8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kxqc6
} r{2].31'
V52C,]qQH
ie~fQ!rf
Utility.log("Thread " + nThreadID + " is over!"); hk!,
bDownOver = true; [H:GKhPC`
//nPos = fileAccessI.write (b,0,nRead); sqpOS!]
} hB}h-i(u
catch(Exception e){e.printStackTrace ();} R~5*#r@f
} SM#S/|.]
} CndgfOF
27 145
;!JX-Jq
//打印回应的头信息 fw|+7 O
public void logResponseHead(HttpURLConnection con) oBNX8%5w
{ T'b/]&0Tio
for(int i=1;;i++) 11y.z^
{ 5+/b$mHZX
String header=con.getHeaderFieldKey(i); kAB+28A
if(header!=null) *xo;pe)9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'tu@`7*
Utility.log(header+" : "+con.getHeaderField(header)); hN_f h J
else Am4^v?q
break; W6Aj<{\F
} 6;[/9
} 1S(\2{Ylo
[&pW&>p3
X:``{!~geo
public void splitterStop() u|OzW}xb7j
{ G>w?9:V}
bStop = true; ~'NpM#A
} \9(- /rE
ta4JWllf
(YYj3#|
} o!toO&=
^>X)"'0+
M9s43XL(&
/* I' ! r
**FileAccess.java $~,}yh;
*//文件访问(定位，写) ]C ~1]7vb
package NetFox; bH\C5zt6(
import java.io.*; mYh5#E41J
%`?;V;{=
C3\E.u?
public class FileAccessI implements Serializable{ "\/^/vn?
_))I.c=v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QOV}5 0
RandomAccessFile oSavedFile; jkF+g$B
long nPos; 5Z9~ &U
Z<ajET`)
F?8BS*r_
public FileAccessI() throws IOException @ 2!C^}d3F
{ .;HIEj zq
this("",0); Cl6m$YUt
} @1qdd~B}
9:%n=URd
`D)Lzm R
public FileAccessI(String sName,long nPos) throws IOException ,]Ro',A&
{ }{5mH:
oSavedFile = new RandomAccessFile(sName,"rw"); wMz-U- z
this.nPos = nPos; %0yS98']g
oSavedFile.seek(nPos); k6O.H
} I%9bPQ
3T|Y}
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public synchronized int write(byte[] b,int nStart,int nLen) j1puB
{ 3duG.iUlL
int n = -1; l@N;sI<O-
try{ 3a#PA4Ql
oSavedFile.write(b,nStart,nLen); SLtSqG7~
n = nLen; n1*&%d'7
} ?h!t$QQ!M
catch(IOException e) -]Q(~'a
{ `l>93A
e.printStackTrace (); -=$% {
} BrJ o!@<
J;UBnCg
q]6_rY.
return n; I#U>5"%\a
} 2'wr={>W
u R\m`
PMgQxM*h
} IS[Vap:
{J~(#i k
g ?afX1Sg
/* JFM"ii{8
**SiteInfoBean.java >[ug zJ
*/ 2wx!Lpr<i_
package NetFox; P</s)"@
_+twqi
60GFVF]'2
public class SiteInfoBean { {~"7vkc+
{r={#mO;p
E@w[&#
private String sSiteURL; //Site's URL 'h-3V8m^e
private String sFilePath; //Saved File's Path $ph0ag+
private String sFileName; //Saved File's Name YC]PN5[1!
private int nSplitter; //Count of Splited Downloading File mEoA#U
b'velj3A
RT%x&j
public SiteInfoBean() 0Injyc*bMF
{//nSplitter的缺省值为5 \\jIl3Z
//default value of nSplitter is 5 ;rd6ko
this("","","",5); \bhOPK>w
} 9~@<-6jE3b
J &!B|TS
)YuRjBcp,"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +}Xr1fr{jw
{ (/"thv5vT{
sSiteURL= sURL; 31~hlp;
sFilePath = sPath; wms1IV%;
sFileName = sName; 2~f6~\4GL+
this.nSplitter = nSpiltter; a{h%DpG
ZjqA30!
NuU'0_")/
} _u>t3RUA
f1A_`$>
_N98vf0o
public String getSSiteURL() Oqpp=7
{ VS?dvZ1cC
return sSiteURL; P: n#S%
} L 5+J ^
U,e'ZRU6
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public void setSSiteURL(String value) #wr2imG6
{ SO`dnf
sSiteURL = value; U\Ct/U&A?
} Hk,lX r
j"5Pe
|K%}}g[<e;
public String getSFilePath() (@ "=F6P
{ v"rl5x
return sFilePath; vF"c
} 5^yG2&>#
K<FKu $=
@7-=zt+f
public void setSFilePath(String value) uJgI<l'|e3
{ LZ{YmD&6]
sFilePath = value; N/K=Ygv.
} zLP],wB
~z5@V5z
F) ?o,
public String getSFileName() \/!ZA[D|E\
{ <P1rqM9^
return sFileName; <"?*zx&
} qU#$2
G*B$%?n
4IZlUJ?j+c
public void setSFileName(String value) /|?F)%v\
{ |H8^
sFileName = value; I~)cYl:|G
} i3\~Qj;1
H)E^!eo
IV0[!D
public int getNSplitter() W<v_2iVu
{ 7F9;Su3.
return nSplitter; Ox^:)ii
} 3YW=||;|Yg
BEWro|]cM
[(|^O>k8c
public void setNSplitter(int nCount) l4KbTKm7
{ ACb/ITu
nSplitter = nCount; s"i~6})K<$
} ,t1vb3
} A[`G^$
4}i*cB`
H-(q#?:
/* )Vg2Jix,]
**Utility.java ~].ggcl`w
*/ :6Pnie
package NetFox; =NZ[${7mq
D<t~e$H
SauH>
public class Utility { dv, C6t2
?g3 ]~;#
]dG\j^e|
public Utility() T1W:>~T5#
{ b#/i.!:a
U]1(&MgV
\0ov[T N.>
} !,Nwts>m
R"3 M[^
//线程睡眠 'tm$q/&
public static void sleep(int nSecond) g6%Z)5D]!
{ b}@(m$W
try{ *tc{vtuu~^
Thread.sleep(nSecond); ,."b3wR[w
} F\:(*1C
catch(Exception e) ,3HcCuT
{ ',{7%G9
e.printStackTrace (); oq$w4D0Z
} L\e>B>u
} ybQP E/9
8:thWGLN
//日志 (PRBS\*G
public static void log(String sMsg) }"_j0ax
{ :$g8Zm,y
System.err.println(sMsg); DI1(`y
} __I/F6{ 9V
^:u?ye;
*5OCqU+g
public static void log(int sMsg) Cqxv"NN
{ C!&y
System.err.println(sMsg); .VM3D0aV
} ghAi{@s$)
} Hx2En:^Gf
I%"'*7U
eEl.. y
/* -.iNNM&a
**TestMethod.java |cDszoT /
*/ 0q,pi qjO
package NetFox; I :)W*SK
k1='c7s
Y]N,.pv=
public class TestMethod { hat>kXm2K
`uo,__y
;AIc?Cg
public TestMethod() .A6lj).:
{ ///xx/weblogic60b2_win.exe tmJgm5v
try{ c|AtBgvf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PB53myDQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XIAeCU
SiteFileFetch fileFetch = new SiteFileFetch(bean); E4i0i!<z
fileFetch.start(); u6Je@e_!
} --fFpM3EvS
catch(Exception e){e.printStackTrace ();} 1J}8sG2`
bMKL1+y(
QI}E4-s8
} U# JIs
wO.iKX;
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public static void main(String[] args) XK ApLz
{ >cN~U3
new TestMethod(); VDGCWg6z
} "i&"* ~
} P"3*lk+w
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