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)); ,D2nUk
} U U@
for(int i=0;i<nEndPos.length-1;i++) b)7v-1N
{ (W5JVk_o
nEndPos = nStartPos[i+1]; K[l5=)G0L
} MY l9 &8
nEndPos[nEndPos.length-1] = nFileLength; I}u&iV`
} qkBCI,X_Y
} `_!R;f
U &RZx&W
m-lTXA(
//启动子线程 <v3pI!)x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =H8Y
for(int i=0;i<nStartPos.length;i++) R<;;Ph
{ o<Qt<*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J*t_r-z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mZ~f?{
nStartPos,nEndPos,i); sE!$3|Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1!Afq}|
fileSplitterFetch.start(); qe|U*K 2_
} @0-vf>e3-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %PC8}++
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q``:[Sz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Lmw4
nEndPos = " + nFileLength); +!$]a^3l
// fileSplitterFetch[nPos.length-1].start(); a;=IOQ
bU$M)
gjn1ha"h%.
//等待子线程结束 1t}
//int count = 0; "x O+
//是否结束while循环 GrI<w.9X
boolean breakWhile = false; wicW9^ik
dZCnQIS
^xQPj6P}
while(!bStop) 3<_=Vyf
{ SLda>I(p7&
write_nPos(); F$jfPy-f
Utility.sleep(500); AA0\C_W0p
breakWhile = true; z@v2t>@3k
X<&Y5\%F
3,1HD_
for(int i=0;i<nStartPos.length;i++) r0q?e`nsA
{ JC iB;!y
if(!fileSplitterFetch.bDownOver) fndbGbl8p
{ RaOLy \
breakWhile = false; Y|ErVf4
break; wY"BPl]b
} Y6m:d&p=}
} 8wMwS6s:
if(breakWhile) <YvW /x
break; a"^rOiXR{
wY3|5kbDj
eu'S~c-l
//count++; h}Lrpr2r
//if(count>4) GK1oS
// siteStop(); 395`Wkv
} 1v 4M*
y7x*:xR[
6N[X:F 3`,
System.err.println("文件下载结束！"); fWyXy%Qq
} >Q:h0b_$U
catch(Exception e){e.printStackTrace ();} U04&z 91"
} W0<2*7s
vURgR
Xn02p,,
//获得文件长度 pO)5NbU
public long getFileSize() kAq#cLprG
{ }8'b}7!
int nFileLength = -1; p$mt&,p
try{ KPA.5,ai
URL url = new URL(siteInfoBean.getSSiteURL()); %e(DPX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YT6dI"48
httpConnection.setRequestProperty("User-Agent","NetFox"); ZqXp f
(XEJd4r
I8Y #l'z
int responseCode=httpConnection.getResponseCode(); 0+/ew8~$
if(responseCode>=400) a}X.ewg
{ t\-|J SZ
processErrorCode(responseCode); %Z*N /nU
return -2; //-2 represent access is error w<Bw2c
} OR}+)n{
U:bnX51D4
)FN$Jlo
String sHeader; #3?}MC
D#gC-,
klnk{R.>|
for(int i=1;;i++) +G)a+r'0Q
{ ^Hz1z_[X@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q 3/J@MC
//Utility.log(in.readLine()); Y|buQQ|
sHeader=httpConnection.getHeaderFieldKey(i); A=wG};%_
if(sHeader!=null) +[}<u--
{ k; >Vh'=X
if(sHeader.equals("Content-Length")) D4sp+
{ HSVl$66
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QOY{j
break; *MQ`&;Qa,
} `1uGU[{x
} k"6&&
else Pbt7T Q
break; IyAD>Q^
} @M"( r"ab
} :*s@L2D6
catch(IOException e){e.printStackTrace ();} D 9UM8Hxi
catch(Exception e){e.printStackTrace ();} U$;UW3-
-b|"%e<'
R2JPLvs
Utility.log(nFileLength); O=6[/oc '
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[&kz4_
return nFileLength; ';v1AX}5q
} }}Z2@}
6"; ITU^v
mF4y0r0
//保存下载信息（文件指针位置） @9R78Zra
private void write_nPos() )S;3WnQ)
{ txE+A/>i9
try{ /fdrf
output = new DataOutputStream(new FileOutputStream(tmpFile)); zO@>)@~
output.writeInt(nStartPos.length); Jt0U`_
for(int i=0;i<nStartPos.length;i++) o#=C[d5BV
{ XlnSh<e
// output.writeLong(nPos); ]B$J8.{q0
output.writeLong(fileSplitterFetch.nStartPos); a ,"
output.writeLong(fileSplitterFetch.nEndPos); G#M0 C>n
} }F"98s W
output.close(); 8H|ac[hXK2
} `YqXF=-
catch(IOException e){e.printStackTrace ();} 0Ua=&;/2
catch(Exception e){e.printStackTrace ();} Pm,.[5uc
} 1}Y3|QxF
%0 i)l|
/4@ [^}x
//读取保存的下载信息（文件指针位置） D$@2H>.-
private void read_nPos() D c;k)z=
{ .(3ec/i4CF
try{ jAU&h@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hRMya#%-
int nCount = input.readInt(); (4Nj3x o
nStartPos = new long[nCount]; IUNr<w<
nEndPos = new long[nCount]; CD%Cb53
for(int i=0;i<nStartPos.length;i++) XMdCQ=
{ .rS. >d^n
nStartPos = input.readLong(); dMCoN8W
nEndPos = input.readLong(); bwj{5-FU
} (.X)=
input.close(); t=9f:,I$
} jsx&h Y%(
catch(IOException e){e.printStackTrace ();} {&UA60~6
catch(Exception e){e.printStackTrace ();} 57=d;Yg e
} K:GEC-
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private void processErrorCode(int nErrorCode) ]^T-X/v9
{ `oH4"9&]k3
System.err.println("Error Code : " + nErrorCode); v5@M 34
} s;Gg
)(_NFpM
<XQwu*_\
//停止文件下载 (m6V)y
public void siteStop() esj6=Gh
{ 2pU'&8
bStop = true; DR,7rT{$
for(int i=0;i<nStartPos.length;i++) dfKGO$}V
fileSplitterFetch.splitterStop(); Ow.DBL)x'>
r/HTkXs I
5+;Mc[V3-
} IvlfX`("
} |:.Uw\z5'
//负责部分文件的抓取 5[4nFa}R:5
**FileSplitterFetch.java s]|tKQGl,
*/ 79D~Mau#
package NetFox; t 7o4 aBl"
1U/RMN3`
)RT?/NW
import java.io.*; W]bgWKd
import java.net.*; x)GheM^
a2tEp+7?
&0tW{-Hv"
public class FileSplitterFetch extends Thread { aKWxLe
^g5E&0a`g
0zkMRBe
String sURL; //File URL 8A.7q
long nStartPos; //File Snippet Start Position EmR82^_:
long nEndPos; //File Snippet End Position d~QM@<SV
int nThreadID; //Thread's ID C=]<R<Xy
boolean bDownOver = false; //Downing is over MkL2I+*
boolean bStop = false; //Stop identical _> x}MW+
FileAccessI fileAccessI = null; //File Access interface 0y+^{@lU
G"OP`OMDc
b9m`y*My
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d9BFeq8
{ o-7{\%+M
this.sURL = sURL; s\pukpf@
this.nStartPos = nStart; p6K~b
this.nEndPos = nEnd; ?|+e*{4k
nThreadID = id; K@{0]6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Bv!{V)$
} Wbei{3~$Y"
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rq4g~e!S
public void run() _#NibW
{ cv-rEHT
while(nStartPos < nEndPos && !bStop) Nw$OJ9$L>
{ Qrg- xu=
M\a{2f7'n
X%j`rQk`
try{ @j_o CDS
URL url = new URL(sURL); h7^&:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R54ae:8
httpConnection.setRequestProperty("User-Agent","NetFox"); I;%1xdPt
String sProperty = "bytes="+nStartPos+"-"; \X _}\_c,d
httpConnection.setRequestProperty("RANGE",sProperty); _uLpU4# ?
Utility.log(sProperty); #qYgQ<TM!
PA ?2K4
<%Nf"p{K
InputStream input = httpConnection.getInputStream(); t(6]j#5
//logResponseHead(httpConnection); hxH6Ii]\
$qz{L~ <
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byte[] b = new byte[1024]; j1%8r*Jj
int nRead; |oLGc!i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $rmxwxz&W:
{ #UoFU{6tM
nStartPos += fileAccessI.write(b,0,nRead); &:&l+
//if(nThreadID == 1) *X/Vt$P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C@eL9R;N1
} R6od{#5H$
yRyXlZC
grzmW4Cw
Utility.log("Thread " + nThreadID + " is over!"); <)wLxWalF
bDownOver = true; QK[^G6TI
//nPos = fileAccessI.write (b,0,nRead); -dA9x~o
} O>qlWPht
catch(Exception e){e.printStackTrace ();} 41<h|WA
} z$R&u=J
} ;mQ|+|F6X
*3fl}l
8sG?|u
//打印回应的头信息 [0y,K{8t
public void logResponseHead(HttpURLConnection con) |ymW0gh7o$
{ hmo4H3g!N
for(int i=1;;i++) L%/>Le}VX
{ W+1nf:AI.
String header=con.getHeaderFieldKey(i); PL{lYexJ
if(header!=null) ?D _4KFr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cM'MgX9
Utility.log(header+" : "+con.getHeaderField(header)); 3 0[Xkz
else oSD=3DQ;
break; iL);bv W
} 1>rQ).eT
} LYECX
v#&;z_I+
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public void splitterStop() i@nRZ$K
{ ?V8Fgd
bStop = true; XXum2eA
} 4"kc(J`c
nUpj+F#
Q4-d|
} 7FcZxu\
(0q`eO2
z2YYxJc&w
/* 9DhM 9VU
**FileAccess.java ygnZ9ikh<-
*//文件访问(定位，写) hRX9Du`$
package NetFox; 0.x+ H9z
import java.io.*; e8("G[P>
Z,2?TT|p
pLCj"D).M
public class FileAccessI implements Serializable{ gi,7X\`KQ
3-hcKE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >y#MEN>?
RandomAccessFile oSavedFile; V'=;M[&
long nPos; x)dLY.'|
J{dO0!7y
Yc]k<tQ
public FileAccessI() throws IOException 4)tY6ds)r|
{ Jw}t~m3
this("",0); [;,E cw^
} fVgK6?<8^
Db|JR
xbhHP2F|
public FileAccessI(String sName,long nPos) throws IOException {AD-p!6G
{ ]rj~3du\
oSavedFile = new RandomAccessFile(sName,"rw"); RNw#sR
this.nPos = nPos; bT2c&VPCE
oSavedFile.seek(nPos); {U_ ,y(V
} 7QTS@o-
6AJ`)8HX
wE.jf.q
public synchronized int write(byte[] b,int nStart,int nLen) m<3. X"-
{ P_0X+Tz
int n = -1; YQC.jnb2
try{ '6qH@r4Z<
oSavedFile.write(b,nStart,nLen); wsB-( 0-
n = nLen; {l$)X
} Ur< (TM
catch(IOException e) Sy <E@1
{ drjNK!XL@
e.printStackTrace (); h SS9mQ
} =<HekiYM
G`%rnu
@JhkUGG]p
return n; )J@[8 x`
} J[?oV;O
jRC{8^98
\Qah*1
} jm<^WQ%Cc
0qFO+nC
) 6QJZ$
/* jW8ad{
**SiteInfoBean.java RP~67L
*/ N*Q*>q
package NetFox; B">Ko3
[rcM32
:!Q(v(M
public class SiteInfoBean { JJ)
VO:
Cj~e` VRhk
private String sSiteURL; //Site's URL W895@
private String sFilePath; //Saved File's Path e"^WXP.t&
private String sFileName; //Saved File's Name h!(# /
private int nSplitter; //Count of Splited Downloading File 6)YckxN^
!1R?3rVQS
/1/'zF&R-
public SiteInfoBean() G2wSd'n*y
{//nSplitter的缺省值为5 0N!rIz
//default value of nSplitter is 5 N~v<8vJq`
this("","","",5); l^bak]9 1
} Pl'lmUR
E.m2- P;4
>wqWIw.w>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +76ao7d.
{ ?H_@/?
sSiteURL= sURL; D]iyr>V6'
sFilePath = sPath; V_$<^z|
sFileName = sName; *^[6uaa
this.nSplitter = nSpiltter; a+v.(mCG
]lGkZyUhI
zwQ#Yvd
} U+B{\38
X=?9-z] QO
~P}ng{x4z
public String getSSiteURL() cy6YajOk7
{ 9 AD*
return sSiteURL; Da[#X`Kp$
} Y]6dYq{k
cCiDe`T\F
t3.;qDy
public void setSSiteURL(String value) RRyD<7s1
{ mnZfk
sSiteURL = value; VgbT/v
} GBS+ 4xL|
7R5ebMW V
GJU(1%-
public String getSFilePath() imM#zy
{ t 4M-;y
return sFilePath; a6:hH@,
} T-4dD
3jfAv@I~
wU'+4N".
public void setSFilePath(String value) J=kf KQV
{ fA1{-JzV<4
sFilePath = value; VPO~veQ
} 3hJ51=_0^
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be-HF;lZe'
public String getSFileName() @`B_Q v@
{ S/eplz;
return sFileName; -0`n(`2
} \goiW;b
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PL31(!`@d
public void setSFileName(String value) N8x&<H
{ .P5'\
sFileName = value; '"Uhw$#t
} $P8AU81
@v&P;=lU
}3WP:Et
public int getNSplitter() op-\|<i
{ ql5&&e=-
return nSplitter; $mAyM+ ph[
} h4ntjk|{i7
p/LV^TQ
GHi'ek<?^
public void setNSplitter(int nCount) Y0Tw:1a
{ uTO%O}D N
nSplitter = nCount; M;AvOk|&
} pIpdVKen
} ^g2Vz4u
M'X,7hZ
@!ja/Y^
/* !YO'u'4<aK
**Utility.java Mg}/gO%o
*/ gE*7[*2?t
package NetFox; qTWQ!
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}{PG^Fc<P
public class Utility { icVB?M,m
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public Utility() |#xBC+
{ 3H>\hZ
*(wxNsK
Ue`Y>T7+!
} vaVV1
g%ys|
//线程睡眠 Xyz/CZPi
public static void sleep(int nSecond) Zv mkb%8
{ ;5T}@4m|r
try{ S5H}
Thread.sleep(nSecond); h~._R6y
} I;?PDhDb
catch(Exception e) Ms3GvPsgv
{ s6}SdmE
e.printStackTrace (); X4'!:&
} t1yfSStp
} >@a7Zzl0H
F_/ra?WVH
//日志 9@Cu5U]
public static void log(String sMsg) i3L2N~:V
{ +4qR5(W
System.err.println(sMsg); >lJTS t5{
} eqOT@~H
TB<$9FCHK
n8\88d
public static void log(int sMsg) K2v[_a~@
{ ?-0, x|ul
System.err.println(sMsg); E 8$S0u;`
} y5^OD63s
} .>}Z3jUrf
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#l9sQ-1Q
/* &(p5z4Df
**TestMethod.java Azr|cKu]
*/ d}|z+D
package NetFox; T>hm\!
XW2ZQMos1
j`Ek:
public class TestMethod { ]|K6Z>V
&?xtmg<d
VS7
public TestMethod() U ){4W0
{ ///xx/weblogic60b2_win.exe 3=Uyt
try{ ?Ycl!0m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nC?Lz1re
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v<(+ l)Ln
SiteFileFetch fileFetch = new SiteFileFetch(bean); $|[N3
fileFetch.start(); BbL]0i
} GZuWAa
catch(Exception e){e.printStackTrace ();} BT$Oh4y4
E1w8d4P,G
c7[Ba\Cr4h
} zR/mz)6_
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public static void main(String[] args) 23'{{@30
{ F$:UvW@e1
new TestMethod(); JnqP`kYbTE
} P)Oe?z;G?
} B"5xs
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