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)); _$x *CP0(
} C_&tOt
for(int i=0;i<nEndPos.length-1;i++) NWcF9z%@
{ D'=`O6pK
nEndPos = nStartPos[i+1]; JIkmtZv
} (bXp1*0 ;
nEndPos[nEndPos.length-1] = nFileLength; wn.0U
} F=lj$?4{
} 5Ww\h
7}?z=LHb3
s7gf7E#Y
//启动子线程 LD"}$vfs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g[Y$SgJ
for(int i=0;i<nStartPos.length;i++) !SNtJi$;v
{ p_N=V. w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z#!Cg*K(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5rhdm?Ls0
nStartPos,nEndPos,i); r F-yD1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e6/} M3B
fileSplitterFetch.start(); 3<SC`6'?
} m)2U-3*iX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -M9 4 F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?q6eV~P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 79fg%cSb
nEndPos = " + nFileLength); vpMv
// fileSplitterFetch[nPos.length-1].start(); ^u<+tV
Mqy`j9FbL
smNr%}_g
//等待子线程结束 a+Nd%hoe
//int count = 0; EZFWxR/
//是否结束while循环 )FCqYCfk
boolean breakWhile = false; ]].21
suSIz 7:
MS)bhZvO
while(!bStop) W>49,A,q
{ {,X(fJ
write_nPos(); 1jb@nxRjO
Utility.sleep(500); O@$i
breakWhile = true; AEJm/8,T
^u74WN
mUw,q;{
for(int i=0;i<nStartPos.length;i++) _X/`4 G
{ _Fjv.VQ,
if(!fileSplitterFetch.bDownOver) ]QQ"7_+
{ NI)nf;C
breakWhile = false; ZvJx01F{
break; +d96Z^KUhv
} bHNaaif}P
} dWSH\wm+
if(breakWhile) M`FL&Ac
break; #wfR$Cd
|Can
<o O_wS@:
//count++; +{Ttv7l_2
//if(count>4) @nK08Kj-
// siteStop(); }ls>~uN
} AmHIG_'
L\5n!(,0
UWp(3FQ
System.err.println("文件下载结束！"); XR(kR{yo
} h";sQ'us
catch(Exception e){e.printStackTrace ();} 191)JWfa
} ;pJ7k23(
KAGq\7
lK0coj1+
//获得文件长度 9b>a<Z
public long getFileSize() 0FBifK
{ U.\kAEJ
int nFileLength = -1; "cZ.86gG`:
try{ FK>rc3 q
URL url = new URL(siteInfoBean.getSSiteURL()); C|+5F,D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :HC{6W`$
httpConnection.setRequestProperty("User-Agent","NetFox"); rHznXME$wZ
w$_ooQ(_;Q
LF8B5<[O
int responseCode=httpConnection.getResponseCode(); %rkUy?=vu
if(responseCode>=400) 3JwmLGj}
{ TX;|g1K
processErrorCode(responseCode); |"arVde
return -2; //-2 represent access is error +-ue={'
} Mppb34y
xJ4T7 )*
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String sHeader; YS9|J=!~
,+XQ!y%
.d;/6HD[y
for(int i=1;;i++) w] VvH"?
{ &}WSfZ0{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q"KH!Bu%P
//Utility.log(in.readLine()); *%8dW
sHeader=httpConnection.getHeaderFieldKey(i); FBe1f1 sm
if(sHeader!=null) y<Z8+/f`f
{ r*$KF!-dg
if(sHeader.equals("Content-Length")) f?)qZPM
{ =^6]N~*,D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -k'=s{iy
break; 6;ICX2Wq'
} ZC05^
} o9JJ_-O"
else }a8N!g
break; r3|vu"Uei
} r]TeR$NJ
} mIOx)`$
catch(IOException e){e.printStackTrace ();} 2e+DUZBoC
catch(Exception e){e.printStackTrace ();} | r2'B
O*CKyW_$t
[qc90)^Q,
Utility.log(nFileLength); wEk9(|
'kp:yI7w
|>m@]s7Z
return nFileLength; ?=6zgb"9-
} /@q_`tU
B<i1UJ5
?;\YiOTda
//保存下载信息（文件指针位置） ]ko>vQ4]3
private void write_nPos() M^H357r%
{ /6g*WX2P1
try{ o;}o"-s
output = new DataOutputStream(new FileOutputStream(tmpFile)); azN<]u@.
output.writeInt(nStartPos.length); yhZ2-*pTg
for(int i=0;i<nStartPos.length;i++) 6*CvRb&
{ ;R}:2
// output.writeLong(nPos); .#CTL|x
output.writeLong(fileSplitterFetch.nStartPos); y "gYv
output.writeLong(fileSplitterFetch.nEndPos); a&9+<
} ho 4~-xmN
output.close(); C&r&&Pw
} g\d|/HVK
catch(IOException e){e.printStackTrace ();} %vgn>A?]1
catch(Exception e){e.printStackTrace ();} h ~v8Q_6
} c.r]w
K%)u zP
0jG8Gmh!
//读取保存的下载信息（文件指针位置） 4;y*y tY*
private void read_nPos() L`3x0u2
{ ~Cm_=[
try{ K<6)SL4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [s"xOP9R
int nCount = input.readInt(); K8daSvc
nStartPos = new long[nCount]; XC%u`UG
nEndPos = new long[nCount]; ch!/k
for(int i=0;i<nStartPos.length;i++) f }P6P>0T
{ 67?O}~jbG
nStartPos = input.readLong(); ) 7w%\i{M
nEndPos = input.readLong(); nF`_3U8e
} K+p7yZJ
input.close(); }}G`yfs}r
} c>mTd{Abi
catch(IOException e){e.printStackTrace ();} v4OroG=^
catch(Exception e){e.printStackTrace ();} #-W a3P
} i_Ol vuy~
~U}0=lRVS
a'r8J~:jy
private void processErrorCode(int nErrorCode) usc"m huQ
{ n|q$=jE
System.err.println("Error Code : " + nErrorCode); clyZD`*
} _<}oBh
n.F^9j+V
K+|G9
//停止文件下载 lsq\CavbM
public void siteStop() L.X"wIs^
{ 8Mg wXH
bStop = true; SI\ O>a9{
for(int i=0;i<nStartPos.length;i++) <5BNcl\ZL
fileSplitterFetch.splitterStop(); >>%m,F[
'A2^K5`3
m?GBvL$
} NpI "XQ
} !-B$WAV
//负责部分文件的抓取 /3#)
**FileSplitterFetch.java r^zra|]
*/ %1h%#/#[
package NetFox; `8M{13fv
t.X8c/,;g
jJbS{1z
import java.io.*; &65I 6
import java.net.*; e>J.r("f
@KJ~M3d0l
"d"6.ND
public class FileSplitterFetch extends Thread { 46[k9T
7fE U5@
;Vv.$mI
String sURL; //File URL y8%QS*
long nStartPos; //File Snippet Start Position tK7v&[cI
long nEndPos; //File Snippet End Position wjy<{I
int nThreadID; //Thread's ID ]Ub"NLYV
boolean bDownOver = false; //Downing is over 0H!J
boolean bStop = false; //Stop identical -RI&uFqOI
FileAccessI fileAccessI = null; //File Access interface :yxP3e%rp
4m1@lnjp
\uG^w(*)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yo^M>^P\N
{ L5DeLF+
this.sURL = sURL; <]Btx;}
this.nStartPos = nStart; 6v?tZ&, G
this.nEndPos = nEnd; 5D+rR<pD}"
nThreadID = id; FeL!%z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?uh%WN6nU]
} =[do([A
aE(DNeG-H
<5O:jd
public void run() P1_6:USBM
{ &[b(Lx|i
while(nStartPos < nEndPos && !bStop) t9~Y ?
{ *)bh6b=7
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T3bYj|rh=
try{ w5<&b1:
URL url = new URL(sURL); aOhi<I`*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lK Ry4~O
httpConnection.setRequestProperty("User-Agent","NetFox"); VPvQ]}g6k
String sProperty = "bytes="+nStartPos+"-"; W %<,GV
httpConnection.setRequestProperty("RANGE",sProperty); r;~7$B)
Utility.log(sProperty); W#9A6ir>
g|Xjw Ti8$
C23Gp3_0/
InputStream input = httpConnection.getInputStream(); zX8'OoEH*9
//logResponseHead(httpConnection); `D $ "K1u
Y>2oU`ly,
QCJf
byte[] b = new byte[1024]; h^v+d*R N
int nRead; E3V_qT8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'i:S=E F
{ f]NaQ!. 7
nStartPos += fileAccessI.write(b,0,nRead); xey?.2K1A
//if(nThreadID == 1) * `3+x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Owz>g4l r
} |33_="
{Q021*xt/
bQ`2ll*(
Utility.log("Thread " + nThreadID + " is over!"); '$h0l-mQ
bDownOver = true; }6To(*
//nPos = fileAccessI.write (b,0,nRead); ;>CM1
} m`&6[[)6~
catch(Exception e){e.printStackTrace ();} RveEA/&&
} mXT{c=N)w
} L"L a|
a(_3271
' -td/w
//打印回应的头信息 ^!6T,7B B
public void logResponseHead(HttpURLConnection con) ]D_ AZI
{ =AP0{
for(int i=1;;i++) [{PmU~RMYf
{ Iuve~ugO
String header=con.getHeaderFieldKey(i); 3Vk<hBw2
if(header!=null) awgS5We|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _iH:>2p5R
Utility.log(header+" : "+con.getHeaderField(header)); lm8<0*;,
else ({<qs}H"
break; | MXRNA~
} UYH&x:WEd
} .2 }5Dc,eR
? @- t.N
]Wn=Oc{F
public void splitterStop() 2,rjy|R`
{ xJ^pqb
bStop = true; %'MR;hQsd8
} .*Axr\x3
wKE}BO >
W]5sqtF;6
} [Qn=y/._r
)U+&XjK
@4wN-T+1
/* $aY:Z_s
**FileAccess.java DfZ)gqp/Av
*//文件访问(定位，写) \|7Y"WEQ
package NetFox; T^@P.zX
import java.io.*; `aL4YH-v
iza.' Mm~
TUi<
public class FileAccessI implements Serializable{ `;Xwv)
K 5AArI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ym wb2]M
RandomAccessFile oSavedFile; -:Jn|=
long nPos; ]m\:XhI*<
S~ZRqL7ZO
w1)SuMFK_
public FileAccessI() throws IOException i%otvDn1
{ t+aE*Q
this("",0); Fv3:J~Yf
} O7xBMqMf
`l-R?C?*!
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public FileAccessI(String sName,long nPos) throws IOException }/VSIS@Z
{ m8 Ti{w(
oSavedFile = new RandomAccessFile(sName,"rw"); 5wI j:s
this.nPos = nPos; &P(vm@*
oSavedFile.seek(nPos); 9=G dj!L
} @l?2",
g?9%_&/})A
JT*Pm"}
public synchronized int write(byte[] b,int nStart,int nLen) ~!ICBF~j
{ S^ JUQx7
int n = -1; +zzS
try{ 8_uh2`+Bvb
oSavedFile.write(b,nStart,nLen); PF]Vt
n = nLen; vW03nt86
} .KxE>lJbqM
catch(IOException e) sX#7;,Ft7
{ % ^&D,
e.printStackTrace (); *Vp$#Rb
} D}K/5iU]a
y5:al7*P
MJ~)CiKgN
return n; `bEum3l\6]
} -P$E)5?^
Yd$64d7,h
N0&#fXO
} K9Bi2/N
?]2OT5@&s
D;OR?NdgvW
/* #mbl4a
**SiteInfoBean.java 'q*:+|"
*/ E']Gh
package NetFox; i ,g<y
6|{uZNz
d5tpw$A
public class SiteInfoBean { p&(~c/0
c$]NXKcA
Zbjj>*2%^
private String sSiteURL; //Site's URL fn'N^
private String sFilePath; //Saved File's Path }{@RO./)[
private String sFileName; //Saved File's Name O:(%m
private int nSplitter; //Count of Splited Downloading File QLAyX*%B
'gv7&$X}4
OvW/{
public SiteInfoBean() bHH=MLZR:
{//nSplitter的缺省值为5 .@;,'Xw1~
//default value of nSplitter is 5 >jBnNA@
this("","","",5); o!M*cyq
} AZadNuL/
T#w *5Qf
d^jIsE`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g63?(+Fz
{ {>=#7e-]
sSiteURL= sURL; c}g:vh
sFilePath = sPath; X5eTj
sFileName = sName; }lt]]094,
this.nSplitter = nSpiltter; N3g?gb"Ex)
QTjOLK$e$
!;YQQ<D
} 2\=cv
T+|V;nP.
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public String getSSiteURL() {cBLm/C
{ h\^> s$
return sSiteURL; r&-Ir3[
} },5_h0
7w=%aW|
S+C^7# lT
public void setSSiteURL(String value) to*<W,I
{ U[8Cg
sSiteURL = value; ()+;KF8
} @7*Ag~MRb
er0ClvB
n"{oj7E0a
public String getSFilePath() :}18G}B
{ GQ8r5V4:
return sFilePath; `g iCytv
} q3E_.{t
'((Ll
g1`/xJz|
public void setSFilePath(String value) @Q atgYu
{ #/9(^6f:
sFilePath = value; R4|<Vp<U2
} x 1"ikp}
GX lFS#`
'yM)>]u"
public String getSFileName() $zBG19 [%
{ \HOOWaapN
return sFileName; E$[\Fk}S
} Az2$\
<&'r_m
R`:NUGR
public void setSFileName(String value) ^50/.Z>
{ ;pNHT*>u,
sFileName = value; $|YIr7?R
} /-39od0
tnmuCz
N+PW,a
public int getNSplitter() ?%h JZm;
{ g~@0p7]Y
return nSplitter; {P#&e>)v{
} RfB""b8]=
=#<hT s
'gojP
public void setNSplitter(int nCount) 5Ffz^;i
{ u-h3xj
nSplitter = nCount; 9Yowz]')
} `8TM<az-L
} $E4W{ad2jW
K,}"v ;||
sHrpBm&O4
/* (;a O%
**Utility.java O.E
*/ `B6{y9J6
package NetFox; rQ'tab.,]
v) q6
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public class Utility { K0\a+6kh
Wx/!Myu
&hba{!`y
public Utility() WL}6YSC
{ =D4EPfQn1
7`tnoTUv
_A)<"z0E
} XI\aZ\v
Rhx7eU#&
//线程睡眠 d#a
public static void sleep(int nSecond) Ik1,?A
{ h{sW$WA
try{ 2ezuP F
Thread.sleep(nSecond); WytCc>oL
} n a2"Sy=Yi
catch(Exception e) -H`G6oMOO
{ R\:C|/6f
e.printStackTrace (); [ylGNuy
} VSZ6;&2^
} RQ{w`>K
S/d})8~.
//日志 S53%*7K.
public static void log(String sMsg) ["Q8`vV0WO
{ J5Fg]O*
System.err.println(sMsg); '{cN~A2b4
} dtM@iDljj
%1VMwqC]E
BdO$
public static void log(int sMsg) e|Sg?ocR
{ ].dTEzL9X
System.err.println(sMsg); e^XijId.
} Ti3BlWQH
} {u.V8%8
0uU%jN$
4&ea*w
/* k #*|-?
**TestMethod.java YF>t{|
*/ C3@.75-E
package NetFox; F`I-G~e
r$v?[x>+K
[k'Ph33c
public class TestMethod { c(#`z!FB
<YeF?$S}
G<jpJ
public TestMethod() U-FA^c;
{ ///xx/weblogic60b2_win.exe 6@XutciK
try{ pXFNK"jm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N^ D/}n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Xb^\{s?b
SiteFileFetch fileFetch = new SiteFileFetch(bean); dBlOU.B
fileFetch.start(); U*&ZQw
} {yb\p9q{Yo
catch(Exception e){e.printStackTrace ();} YRp\#pVnZ
J82{PfQ"
~2H7_+.#
} Jl]]nOBQ/
kmc9P&
u=E?N:I~F
public static void main(String[] args) '-i tn
{ =|U2 }U;
new TestMethod(); R^B2J+O
} @i{JqHU"
} ImV54h'
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