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)); MEEAQd<*
} <yZP|_
for(int i=0;i<nEndPos.length-1;i++) 2B^~/T<\
{ sxo;/~.p
nEndPos = nStartPos[i+1]; u+i(";\
} lX"bN=E?!
nEndPos[nEndPos.length-1] = nFileLength; V]rhVMA
} ;1v=||V
} 0Q'v HZ"
& 1[y"S
]u+MTW;
//启动子线程 S_2"7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `)$`-Pw*
for(int i=0;i<nStartPos.length;i++) L1wZU,o
{ P.cO6+jGR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H'EY)s Hi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZRnL_z~
nStartPos,nEndPos,i); w:}C8WKw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3qtr9NI
fileSplitterFetch.start(); vf<UBa;Xm
} M ?*Tf&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gg|M+M?+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r0\?WoF2C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bj}=8k0
nEndPos = " + nFileLength); O}C)~GU
// fileSplitterFetch[nPos.length-1].start(); ,^ 7 CP
zie=2
MLV:U
//等待子线程结束 '.Z4 hHX
//int count = 0; ^;r+W-MQ
//是否结束while循环 4=xq:Tf
boolean breakWhile = false; "b]#MO}P
dCeX}Z
e0 u,zg+m
while(!bStop) U'y,YtF@
{ :I \9YzSs@
write_nPos(); (bv,02
Utility.sleep(500); hL!QLiF:
breakWhile = true; L,?/'!xV
h*3{6X#(/
R"3 M[^
for(int i=0;i<nStartPos.length;i++) 'tm$q/&
{ {oUAP1V^
if(!fileSplitterFetch.bDownOver) JO=1ivZl
{ h%TLD[[/jr
breakWhile = false; WhFS2Jl0
break; \3zp)J
} rQJ"&CapT
} K"\MU
if(breakWhile) Hm fXe
break; _9@ >;]
>.<ooWw
YTQps&mD.
//count++; -Wc~B3E|
//if(count>4) _6MdF<Xb/
// siteStop(); B[F-gq-
} KzphNHd
:$g8Zm,y
DI1(`y
System.err.println("文件下载结束！"); __I/F6{ 9V
} J[@um:
catch(Exception e){e.printStackTrace ();} 3F+Jdr'
} cSK&[>i)4
0y~<%`~
f<<rTE6
//获得文件长度 ,%W<O.
public long getFileSize() XV>&F{
{ >o~Z>lr
int nFileLength = -1; eEl.. y
try{ T5|c$doQ
URL url = new URL(siteInfoBean.getSSiteURL()); |cDszoT /
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0q,pi qjO
httpConnection.setRequestProperty("User-Agent","NetFox"); MT6/2d
P`jL]x
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int responseCode=httpConnection.getResponseCode(); C5@V/vA
if(responseCode>=400) :!Ig- +W
{ l-Nly>~
processErrorCode(responseCode); iev>9j
return -2; //-2 represent access is error l&W;b6L
} y3eHF^K+$
KrcgIB8X
A6{b?aQ
String sHeader; B$vr'U
#yW\5)
VK:8 Nk_y
for(int i=1;;i++) AIRr{Y
{ FT89*C)oD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y(a!YicA?
//Utility.log(in.readLine()); eV7u*d?
sHeader=httpConnection.getHeaderFieldKey(i); U# JIs
if(sHeader!=null) wO.iKX;
{ Q@-ovuxi
if(sHeader.equals("Content-Length")) ` ;)ZGY\
{ o.7{O,v
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kKiA
break; L]d-33.c!H
} EQ<RDhC@b
} nSx]QREL!
else [/ M`
break; DmqSQA
} . +
} A],ooiq<
catch(IOException e){e.printStackTrace ();} :+rUBYWx
catch(Exception e){e.printStackTrace ();} VDbI-P&c
P"_$uO(5x
} JiSmi6o
Utility.log(nFileLength); qO@@8/l
bKDA!R2
][;G=oCT
return nFileLength; $`VFdAe
} 57,dw-|xi
TDtAmk
]N{0:Va@D
//保存下载信息（文件指针位置） Anm=*;*M`
private void write_nPos() beXNrf=bG
{ sJG5/w
try{ hk>;pU(
output = new DataOutputStream(new FileOutputStream(tmpFile)); MJ{%4S{K,p
output.writeInt(nStartPos.length); )ChqATKg
for(int i=0;i<nStartPos.length;i++) kA wNly
{ i38[hQR9a
// output.writeLong(nPos); [KJ q
output.writeLong(fileSplitterFetch.nStartPos); 5W? v'"
output.writeLong(fileSplitterFetch.nEndPos); ,*I@
} gI]GUD-
output.close(); H%F>@(U
} :G5uocVk
catch(IOException e){e.printStackTrace ();} ^dm!)4W
catch(Exception e){e.printStackTrace ();} qk/:A+
} %G3(,Qz
O) atNE
3AcD,,M>>
//读取保存的下载信息（文件指针位置） eqAW+Ptx
private void read_nPos() zDTv\3rZ4X
{ xdvh-%A4
try{ 3< Od0J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :4gLjzL
int nCount = input.readInt(); bM,1f/^
nStartPos = new long[nCount]; M~Ttb29{
nEndPos = new long[nCount]; Cq)IayD@
for(int i=0;i<nStartPos.length;i++) O1&b]C#
{ XFVV},V
nStartPos = input.readLong(); tWeFEVg
nEndPos = input.readLong(); >slm$~rv
} 5Por "&%
input.close(); }J:+{4Yn
} 5N[9 vW
catch(IOException e){e.printStackTrace ();} Z;l`YK^-
catch(Exception e){e.printStackTrace ();} [U@;\V$
} _ *f
``VW;l{
PQN@JaD
private void processErrorCode(int nErrorCode) +HT1ct+dI
{ -_C#wtC
System.err.println("Error Code : " + nErrorCode); vQ}6y
} PxS4,`#~
7JJ/D4uT
$Xm6N@
//停止文件下载 I pzJ#
public void siteStop() bg,9@ }"F
{ Cqii}
bStop = true; 6z0@I*
for(int i=0;i<nStartPos.length;i++) XQ%4L-rhN
fileSplitterFetch.splitterStop(); YKmsQ(q`N
azQD>
ev1 W6B-a
} 8mTM$#\
} 1NQbl+w#I
//负责部分文件的抓取 lKWPTCU
**FileSplitterFetch.java ~S,p?I
*/ mrIh0B:`
package NetFox; 7\]E~/g
zmj"fN{\
t\P<X^d%
import java.io.*; ;5-r_D;9
import java.net.*; "tFxhKf
2*"Fu:a"`I
.MQ^(
public class FileSplitterFetch extends Thread { qy)_wM
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K~=UUB
String sURL; //File URL sJwyj D$b
long nStartPos; //File Snippet Start Position /sM~Uq?
long nEndPos; //File Snippet End Position AfeCK1mC@
int nThreadID; //Thread's ID fXI:Y8T
boolean bDownOver = false; //Downing is over DejA4XdW
boolean bStop = false; //Stop identical oi}i\: hI
FileAccessI fileAccessI = null; //File Access interface ~qe%Yq
7dsefNPb
sGh(#A0Pt
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y!iZW
{ 1f",}qe;
this.sURL = sURL; }_=eT]
this.nStartPos = nStart; su*Pk|6%
this.nEndPos = nEnd; m]i @ +C
nThreadID = id; kmzH'wktt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3(C\.oRc
} DCqY|4Qc
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]Q]W5WDe:
public void run() f&v9Q97=
{ 9zYVC[o
while(nStartPos < nEndPos && !bStop) ctE\ q
{ uqz]J$
}D+}DPL{^
X7k.zlH7T
try{ aQ:5d3m0
URL url = new URL(sURL); r.7$&BCng
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )95f*wte
httpConnection.setRequestProperty("User-Agent","NetFox"); `+6R0Ch
String sProperty = "bytes="+nStartPos+"-"; lHgs;>U$
httpConnection.setRequestProperty("RANGE",sProperty); Xpzfm7CB/
Utility.log(sProperty); cGjPxG;
\&U>LwZd?
Ft}@1w5
InputStream input = httpConnection.getInputStream(); 9tF9T\jW
//logResponseHead(httpConnection); jKt7M>P
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2-Y<4'>
byte[] b = new byte[1024]; TB0 5?F
int nRead; !K|5bK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mI74x3 [
{ <b,~:9*?
nStartPos += fileAccessI.write(b,0,nRead); oudxm[/U
//if(nThreadID == 1) [eTSZjIN7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9on@Q_7m
} ~69&6C1Ch
)1X#*mCxk
P.gb1$7<
Utility.log("Thread " + nThreadID + " is over!"); '7O3/GDK
bDownOver = true; Gea\,{E9xA
//nPos = fileAccessI.write (b,0,nRead); 13taFVdU
} {<<U^<6}
catch(Exception e){e.printStackTrace ();} 6gc>X%d`K
} ]+X@ 7
} s[UHe{^T
/ m=HG^!
B}^w_C2
//打印回应的头信息 Hh+ 2mkg
public void logResponseHead(HttpURLConnection con) eM8}X[
{ '-zD
for(int i=1;;i++) dAuJXGo
{ 82l~G;.n3
String header=con.getHeaderFieldKey(i); Bve.C
if(header!=null) HTG%t/S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~3<> 3p
Utility.log(header+" : "+con.getHeaderField(header)); wmTb97o
else d3xmtG {i
break; F6z%VWU
} ;+"+3
} )ut&@]
F w?[lS
M3.do^ss
public void splitterStop() {.XEL
{ YPxM<Gfa8
bStop = true; Yw-G'
} ov, hI>0!D
(!:,+*YY
YOcO4
} 7Op>i,HZk\
v?geCe=ng
Rb'|EiNPw
/* @{25xTt
**FileAccess.java 0)gdB'9V_
*//文件访问(定位，写) \kZ?
package NetFox; RCpR3iC2
import java.io.*; ff^=Ruf$
W)bLSL]`E
1jcouD5?H
public class FileAccessI implements Serializable{ }~L.qG
E 7{U|\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H*}y^)x
RandomAccessFile oSavedFile; ~A\GT$
long nPos; > ;*b|Ik
|!4K!_y
o4Om}]Ti
public FileAccessI() throws IOException ln6d<; M5
{ a^I\ /&aw'
this("",0); F'21jy&
} ~nay"g:
.:F%_dS D
LU!a'H'Q
public FileAccessI(String sName,long nPos) throws IOException 9w7n1k.
{ 4\iOeZRf
oSavedFile = new RandomAccessFile(sName,"rw"); oG_~q w|h
this.nPos = nPos; T{-CkHf9Q
oSavedFile.seek(nPos); fbe[@#:
} \XZ/v*d0
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``hf=`We
public synchronized int write(byte[] b,int nStart,int nLen) ~x1$h#Cx'
{ !2f[}.6+
int n = -1; asppRL||
try{ R\!2l|_
oSavedFile.write(b,nStart,nLen); I=`U7Bis"
n = nLen; Fj2BnM3#
} ;~m8;8)
catch(IOException e) uxr #QA
{ #V~me
e.printStackTrace (); a.k.n<
} 0Qf,@^zL*
P/W XaE4
[M=7M}f;
return n; QTk}h_<u
} !$gR{XH$]
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VA#"r!1
} I&x=;
9y"@(
0AL=S$B)
/* p8Qk'F=h
**SiteInfoBean.java fHx*e'eA
*/ vdc\R?
package NetFox; ek*rp`y]
x??+~$}\*-
|ATvS2
public class SiteInfoBean { +%h8r5o1
c(xrP/yOwi
Ng2twfSl$
private String sSiteURL; //Site's URL Z 2V.3
private String sFilePath; //Saved File's Path L>Fa^jq5
private String sFileName; //Saved File's Name 86=}ZGWd
private int nSplitter; //Count of Splited Downloading File Ga^"1TZ x
iu=7O
,/Z%@-rF
public SiteInfoBean() ;n*.W|Uph
{//nSplitter的缺省值为5 Yi%;|]
//default value of nSplitter is 5 ymhtX6]
this("","","",5); qN9(S:_Px
} Kqb#_hm
y51e%n$
NJWA3zz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I-]?"Q7Jz
{ .ypL=~Rp
sSiteURL= sURL; ^@s1Z7
sFilePath = sPath; Ot_]3:`J~
sFileName = sName; 6]WAUK%h
this.nSplitter = nSpiltter; |\pj;XU
h+g_rvIG*
/NI;P]s.
} y.mda:$~=
Z&+ g;(g
ctZ uA+
public String getSSiteURL() FrGgga$
{ hF~n)oQ
return sSiteURL; \/r}]Vz
} PR#exm&
k<CJ{u0<
7rc0yB
public void setSSiteURL(String value) X9W@&zQ
{ X!TpYUZ'
sSiteURL = value; Tztu}t]N
} [ )Iv^ U9
;u_X)
l*Gvf_UH
public String getSFilePath() @zW]2 c
{ -A^_{4X
return sFilePath; +SR+gE\s0
} P^~yzI
_7Ju
] vHF~|/-
public void setSFilePath(String value) g[' ^L+hd
{ WUn]F~Lt
sFilePath = value; u5`u>.!
} -:+|zF@f
oM>l#><nq
~D j8z+^
public String getSFileName() Cn34b_Sbd
{ ?Jm^<
return sFileName; ].w4$OJ?
} v!~fs)cdE|
MS~(D.@ZS
!GjQPAW
public void setSFileName(String value) V(I8=rVH
{ QOGvC[*`<T
sFileName = value; i+ ?^8#
} C_}]`[
{H>gtpVy
mp1@|*Sn
public int getNSplitter() F]O`3e=!
{ Cw3a0u
return nSplitter; ?=sDM& '
} J/y83@
@Md/Q~>
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public void setNSplitter(int nCount) <`=j^LU
{ UERLtSQ
nSplitter = nCount; .5_2zat0H
} 2`K=Hby
} gh]cXuph
ZPLm]I\]
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/* SwGx?U
**Utility.java Mk 6(UXY
*/ Qz1E 2yJ
package NetFox; `r6,+&
UcHJR"M~c
Rsm^Z!sn
public class Utility { yS'I[l
tCH!my_
rpha!h>w1%
public Utility() q"lSZ; 'E
{ -=Q*Ml#I
~!d\^Z^i
9s q
} V~3a!-m\
N#_H6TfMG
//线程睡眠 L,/%f<wd
public static void sleep(int nSecond) .W%)*&WH\
{ b{&)6M)zo
try{ Dcgo%F-W
Thread.sleep(nSecond); ?dg[:1R}
} Se}c[|8
catch(Exception e) j3V -LnA
{ 194)QeoFw
e.printStackTrace (); CY5Z{qiX
} )mT<MkP
} S9y}
v@L;x [Q
//日志 U?Zq6_M&
public static void log(String sMsg) 6<QQ@5_
{ @Cyvf5|bL
System.err.println(sMsg); 4xje$/_d
} *w\W/Y
$Ds2>G4c
B~ GbF*j
public static void log(int sMsg) 77f9(~ZnT
{ N=}A Z{$
System.err.println(sMsg); 83_h J
} 013x8!i
} #=A)XlZMd
e X|m
AQvudx)@"
/* 6A-|[(NS
**TestMethod.java /W<;Z;zk
*/ G5 WVr$
package NetFox; |u<7?)mp
wlqksG[B
^6V[=!& H
public class TestMethod { "ze|W\Bv!
&j"?\f?
db7B^|Di
public TestMethod() g8% &RG
{ ///xx/weblogic60b2_win.exe #q=Efn'
try{ +a+Om73B2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '-~~-}= sJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1>h]{%I
SiteFileFetch fileFetch = new SiteFileFetch(bean); u&7[n_
fileFetch.start(); zRr*7G
} #)O65GI
catch(Exception e){e.printStackTrace ();} aX'*pK/-
sDlO#
%P|/A+Mg"
} sUQ@7sTj
hHnYtq
}19\.z&J
public static void main(String[] args) \_f(M|
{ n{mfn*r.
new TestMethod(); +ye3HGD
} m;QMQeGz
} w<(pl%
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