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)); gLRDd~H
} Omi/sKFMi
for(int i=0;i<nEndPos.length-1;i++) gZiwXb
{ X:lStO#5
nEndPos = nStartPos[i+1]; Y^nm{;G+
} GKKDO+A=!
nEndPos[nEndPos.length-1] = nFileLength; tyWDa$u,u
} d0i|^
} &KY!a0s
rP}[>
i5=~tS
//启动子线程 @t;726
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M~n./wyC
for(int i=0;i<nStartPos.length;i++) 1rS8+!9C
{ $U7#3-'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nEPTTp+B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *U}ztH-+/
nStartPos,nEndPos,i); zkiwFEHA=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !??g:2
fileSplitterFetch.start(); K9]zUe&#w
} fZ&' _
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "LSzF_mK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $ai;8)C6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5^R?+<rd
nEndPos = " + nFileLength); X7[gfKGL)N
// fileSplitterFetch[nPos.length-1].start(); $$uMu{?0i
M%Ksyr9
vt nT
//等待子线程结束 CZ'm|^S
//int count = 0; I~6 o<HO
//是否结束while循环 $4}G
boolean breakWhile = false; 0qIg:+l+
B,&QI&k`~
yn"4qC#Z
while(!bStop) tj*/%G{Y
{ +KD7Di91<K
write_nPos(); ;4(}e{
Utility.sleep(500); Pjn{3/*wi
breakWhile = true; j@w1S[vt
:`Ep#[Wvo
d S'J@e=#
for(int i=0;i<nStartPos.length;i++) l^$'6q"
{ $:\`E56\
if(!fileSplitterFetch.bDownOver) 5KDCmw
{ oH!O{pQK}
breakWhile = false; + ~5P7dh6
break; N'-[>w7vK2
} ,tcUJ}l
} 89;@#9
if(breakWhile) 6Ol9P56j
break; H9PnJr8 \
1q@R04i
4P"bOt5izR
//count++; kN78j
//if(count>4) I{r*Y9
// siteStop(); l^OflZC~
} ZHa>8x;Mjl
Yb4ku7}
qTN%9!0@9
System.err.println("文件下载结束！"); 9(nq 4HvI
} cs?WE9N
catch(Exception e){e.printStackTrace ();} 1_#;+S
} E1tCY.N{
T1*.3_wtP
k].swvIi
//获得文件长度 D7T|K :F)
public long getFileSize() E>f{j:M
{ l)dE7$H
int nFileLength = -1; $B_%MfI
try{ gua7<z6=eh
URL url = new URL(siteInfoBean.getSSiteURL()); (ie%zrhS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -*MY7t3
httpConnection.setRequestProperty("User-Agent","NetFox"); jU7[z$GX
""XAUxo
,a,2I
int responseCode=httpConnection.getResponseCode(); xY#J((-iH
if(responseCode>=400) (3lA0e`Y
{ HKJBR)T
processErrorCode(responseCode); o5 fV,BJZO
return -2; //-2 represent access is error [U8/nT
} -egnMc67
DyCzRkH
R y#C#0
String sHeader; Hz."4nhv
~59lkr8
:i4(cap&}F
for(int i=1;;i++) -{ 1P`&G
{ <Q/)SN6_E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GCq4{_B\Q
//Utility.log(in.readLine()); L!zdrCM
sHeader=httpConnection.getHeaderFieldKey(i); Q}OloA(+
if(sHeader!=null) op5`#{
{ 8cG`We8l&
if(sHeader.equals("Content-Length")) q(:L8nKT]
{ \U]K!K=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1(dKb
break; aEvbGo
} [}ja\!P
} +:-xV
else )J> dGIb
break; 1=C12
} NytTyk)
} T|wz%P<J
catch(IOException e){e.printStackTrace ();} h!K" ;qw
catch(Exception e){e.printStackTrace ();} L;u5
|[Fb&x
]6[+tpx
Utility.log(nFileLength); 3CjixXaA$
QfAmGDaYQ
BK+P
return nFileLength; 05T?c{ ;
} i79$D:PcLa
&C+2p
XLCqB|8`V
//保存下载信息（文件指针位置） Z>bNU
private void write_nPos() _!qD/[/
{ | U"fhG=g
try{ EI6kBRMo
output = new DataOutputStream(new FileOutputStream(tmpFile)); su%-b\8K
output.writeInt(nStartPos.length); GI/NouaNfm
for(int i=0;i<nStartPos.length;i++) 8]^|&"i.\d
{ T`fT[BaY
// output.writeLong(nPos); #jg-q|nd
output.writeLong(fileSplitterFetch.nStartPos); bUm%#a
output.writeLong(fileSplitterFetch.nEndPos); jaodcT0
} IRx%L?
output.close(); 7$Z_'GJ]1C
} 5(J?C-Pk
catch(IOException e){e.printStackTrace ();} D^6iQW+.P
catch(Exception e){e.printStackTrace ();} g/!MEOVx
} UIyLtoxu
OxGfLeP.R!
>fI\f <ez
//读取保存的下载信息（文件指针位置） UWC4PWL,>C
private void read_nPos() YR-G:-(#b
{ h`\$8oV
try{ UHvA43
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lWj*tnnn[
int nCount = input.readInt(); 7)jN:+4N
nStartPos = new long[nCount]; 6[k<&;
nEndPos = new long[nCount]; TS9<uRO0
for(int i=0;i<nStartPos.length;i++) (LmU\Pe%
{ cYK:Y!|`F
nStartPos = input.readLong(); F&R*njJcc
nEndPos = input.readLong(); M-i3_H)
} 9X4[Zk
input.close(); SR?mSpq5
} 2e%\aP`D2
catch(IOException e){e.printStackTrace ();} *cXq=/s
catch(Exception e){e.printStackTrace ();} ZBpcC0 z
} 5H XF3
vRC >=y*=
&lSNI5l
private void processErrorCode(int nErrorCode) ,4t6Cq!
{ s0;a j<J
System.err.println("Error Code : " + nErrorCode); InbB2l4G
} `i cs2po
GJcxqgk$
4z(B`t~7
//停止文件下载 xRacgny:I
public void siteStop() \XV8t|*
{ FqA4 OU
bStop = true; %AA&n*m
for(int i=0;i<nStartPos.length;i++) ]b%U9hmL^f
fileSplitterFetch.splitterStop(); ZN$%\,<
b`D]L/}pr
(Q=o9o:b
} SkmTW@v
} -`XS2
//负责部分文件的抓取 O)vGIp?f't
**FileSplitterFetch.java &Jj|+P-lY
*/ Jk>vn+q8P^
package NetFox; T.;{f{
["Ts7;q9[
{Z8GG
import java.io.*; UMRFTwY
import java.net.*; lL:!d.{
4E5;wH
Rkg8
public class FileSplitterFetch extends Thread { NJsaTBT
U&BCd$
KLW5Ad:/rI
String sURL; //File URL T(x@gwc
long nStartPos; //File Snippet Start Position L5x;#\#p
long nEndPos; //File Snippet End Position WyatHC
int nThreadID; //Thread's ID ?K7uy5Y
boolean bDownOver = false; //Downing is over r6uN6XCM
boolean bStop = false; //Stop identical u:|^L]{
FileAccessI fileAccessI = null; //File Access interface qH4|k2Lm
$+GDPYm'
u*2?Gky
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zO"De~[9
{ v(yJGEf0
this.sURL = sURL; "JSIn"/
this.nStartPos = nStart; ,M{G X
this.nEndPos = nEnd; g@!U^mr*3
nThreadID = id; v; i4ZSV^A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lM4Z7mT /
} )1#/@cU
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?{"r(
public void run() ^PNDxtd|v
{ k5aB|xo
while(nStartPos < nEndPos && !bStop) @z ",1^I
{ #tu>h
hQj@D\}
} uS0N$4
try{ N!~]D[D
URL url = new URL(sURL); b_nE4>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M;y*`<x
httpConnection.setRequestProperty("User-Agent","NetFox"); aBReIK o
String sProperty = "bytes="+nStartPos+"-"; tWy.Gz\
httpConnection.setRequestProperty("RANGE",sProperty); pt.V^a
Utility.log(sProperty); [nig^8
?}8r h%
Jg=!GU/::
InputStream input = httpConnection.getInputStream(); "!zJQl@
//logResponseHead(httpConnection); [yN+(^i
./XX
SZe55mK`
byte[] b = new byte[1024]; wl]3g
int nRead; _"Bj`5S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M#o.O?.`
{ nQOdM#dP
nStartPos += fileAccessI.write(b,0,nRead); I?g}q,!]
//if(nThreadID == 1) IXtG 36O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8Y`g$2SZ^8
} .kU^)H"l
~|S0E:*.
(CIcM3|9C
Utility.log("Thread " + nThreadID + " is over!"); Wrb[\ ?-
bDownOver = true; y*^UGJC:
//nPos = fileAccessI.write (b,0,nRead); }#D=Rf?2\P
} ;dUKFdKH}
catch(Exception e){e.printStackTrace ();} nktGO
} ZAfuW^r
} FulFEnSV
A{q%sp:3~
,on]Fts
//打印回应的头信息 W{'hn&vU
public void logResponseHead(HttpURLConnection con) R]%"YQ V
{ fdKE1,;
for(int i=1;;i++) FhY#3-jH
{ KX9IC5pR
String header=con.getHeaderFieldKey(i); yC1OeO8{
if(header!=null) {p1`[R&n#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %dPk,Ylz
Utility.log(header+" : "+con.getHeaderField(header)); &J2UAmB
else s9sl*1n1m`
break; FtyT:=Kpc
} |#o' =whTl
} VB*c1i
4Pc-A
wJ2cAX;"
public void splitterStop() nE8z1hBUq
{ "|Q.{(|kO1
bStop = true; 1ygEyC[1
} G(wK(P0j
BH {z]a
:'F,l:
} ,zx{RDI
c6vJ;iz
}nPt[77U_7
/* *$%~/Q@]
**FileAccess.java *d=}HO/
*//文件访问(定位，写) <J+Oh\8tad
package NetFox; rd0Fd+t/
import java.io.*; vVo'f|fW
3?V'O6
`{{6vb^g
public class FileAccessI implements Serializable{ J8S$YRZ_
ho{%7\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 neM)(` gp
RandomAccessFile oSavedFile; G 0pq'7B
long nPos; :Y/aT[
3>VL>;75[
GYQ:G=
public FileAccessI() throws IOException A@< !'
{ HcIJ&".~
this("",0); A)9]^@,
} ]pe7I P
wnd #J `
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public FileAccessI(String sName,long nPos) throws IOException R4;1LZ8XzS
{ wp1O*)/q
oSavedFile = new RandomAccessFile(sName,"rw"); qc,EazmU
this.nPos = nPos; xwsl$Rj
oSavedFile.seek(nPos); ]>)shH=Yx
} l[[`-f8j
_Kaqx"D
BN]o!Y
public synchronized int write(byte[] b,int nStart,int nLen) j7&#R+f
{ M**Sus87Q
int n = -1; gD)M7`4
try{ s3A(`heoq
oSavedFile.write(b,nStart,nLen); 9U<WR*H
n = nLen; [VXQ&
} @xo8"kl
catch(IOException e) }bw^p.ci
{ &cyB}Gv
e.printStackTrace (); d>F7i~W
} ;/+<N
[/hoNCH!
zu?112-v2
return n; -x6_HibbD
} [x7Rq_^
gnN>Rl 5_
'Y2$9qy-L
} XHJdynt/
gKTCfD~
e}2?)B`[
/* A7YCSjB
**SiteInfoBean.java {91Y;p C
*/ <#BK(W~$
package NetFox; y]{b4e
?yAb=zI1b
e:-pqZT`
public class SiteInfoBean { xS@jV6E~
(^B1Kt!<
prS%lg>
private String sSiteURL; //Site's URL /Hk})o_
private String sFilePath; //Saved File's Path Y{j~;G@Wl
private String sFileName; //Saved File's Name `/m]K~~
private int nSplitter; //Count of Splited Downloading File hb8oq3*x
/[Fk>Vhp
^3sv2wh^|8
public SiteInfoBean() ?pJ2"/K
{//nSplitter的缺省值为5 Ma?uB8o+~
//default value of nSplitter is 5 Z*3RI5)dx
this("","","",5); W!ug^2"
} 4IZAJqw(*
_s#J\!F
WVQHb3Pe0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7n .A QII
{ C\"C12n{
sSiteURL= sURL; Hvz;[!
sFilePath = sPath; Nz{qu}dt
sFileName = sName; _gK}Gi?|
this.nSplitter = nSpiltter; v,Kum<oi?
kPy7e~
!Usmm8!K
} 8?L-3/
,~$sJ2 g7
g,YF$:e
public String getSSiteURL() BPW.&2?<
{ V+sZ;$
return sSiteURL; nO6UlY
} 2va[= >_
p?Ux1S
]{i0?c
public void setSSiteURL(String value) =zAFsRoD_B
{ ?8grK
sSiteURL = value; ecl6>PS$'
} M1P;x._n
cyd_xB5K
)ty>{t
public String getSFilePath() h{HpI 0q4
{ k:/Z6TLk3
return sFilePath; ^`xS|Sq1D
} ]D@aMC$#
'$yy
r4FSQ$[9w
public void setSFilePath(String value) FDiDHOR
{ ,^ -%<
sFilePath = value; \s8h.xjU
} C-49u<;,
gYho$E
yAGQD[ih
public String getSFileName() =?Co<972Z
{ Q!-"5PX
return sFileName; yWc%z6dXC
} Pt-mLINvG
:k_)Bh?+
#Z]Cq0=
public void setSFileName(String value) h3>u[cX%
{ b't6ekkN
sFileName = value; :L:] 3L
} \A!Iln
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WB (?6"
public int getNSplitter() "<^ Vp-7r
{ Y._ACQG3
return nSplitter; Qe7 SH{
} o^uh3,.
Ia9!ucN7DA
?o]NV
public void setNSplitter(int nCount) PCDvEbpG
{ "E5=AWd
nSplitter = nCount; "_dJ4<8
} 4u2_xbT
} #EKnjh=Uq
e=jtF"&
qoph#\
/* fk2Uxg=[
**Utility.java A&KY7[<AC{
*/ 9l&G2o
package NetFox; |tY6+T}
S:2 xm8 i
H`3w=T+I
public class Utility { <VN< ~sz
DB jUHirK
Q[`2?j?
public Utility() .Xxxz Wyk
{ "AWk jdj
K;`*n7=IA
1-4[w *u>
} w3fD6$
JqN$B\J,
//线程睡眠 NXOvC!<
public static void sleep(int nSecond) #N=_-
{ 2gvS`+<TP
try{ Mns=X)/hc
Thread.sleep(nSecond); E[CvxVCx
} Vhm^<I-d
catch(Exception e) sdewz(xskj
{ v<0S@9~
e.printStackTrace (); +tlbO?
} nu|?F\o!
} >NpW$P{'
Y8mv[+Z
//日志 u7p:6W
public static void log(String sMsg) ZkMHy1
{ (Zy=e?E,
System.err.println(sMsg); hL;??h,!_
} 1mEW]z
O1]XoUH<
9 771D
public static void log(int sMsg) aO<H!hK
{ cwUor}<|
System.err.println(sMsg); !VfVpi+-
} )pey7-P7g5
} FQJFq6l
2NL|_W/
;ov}%t>UD
/* pAEJ=Te
**TestMethod.java ~3Z(0gujD
*/ Xn<|6u
package NetFox; D{t0OvQag
h!hv{c
+hT9V1'-D
public class TestMethod { 5'0kf7
>R/^[([;]
r^\Wo7q
public TestMethod() NXE1v~9V
{ ///xx/weblogic60b2_win.exe "yXqf%CGE
try{ Y}x_ud,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zWdz9;=_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I|mxyyf
SiteFileFetch fileFetch = new SiteFileFetch(bean); k"FY &;G(G
fileFetch.start(); Lr>4~1:`
} { lZ<'p
catch(Exception e){e.printStackTrace ();} {\=NZ\
r2Q) Q
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} g{7?#.7
><@& &u.
69C ss'
public static void main(String[] args) qkyYt#4E
{ u-dF~.x
new TestMethod(); E~Y%x/oX
} 9l7 youZ]
} Q[Tbdc%1EG
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