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)); ~p{ fl?
} r!c7{6N
for(int i=0;i<nEndPos.length-1;i++) Va$JfWef
{ %'MR;hQsd8
nEndPos = nStartPos[i+1]; Tffdm
} |!cM_&
nEndPos[nEndPos.length-1] = nFileLength; mr+8[0
} &4m;9<8\
} Ubv_a
es1'z.UJ
`L @`l
//启动子线程 eY\!}) 5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YR.f`-<Z
for(int i=0;i<nStartPos.length;i++) PG*FIRDb
{ SJO^.[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `aM8L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %(~8a
nStartPos,nEndPos,i); WYW@%t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L[Y|K%;~
fileSplitterFetch.start(); d[&Ah~,
} lT+N{[kLt*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D n}TO*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TnLblkX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (*G'~gSX
nEndPos = " + nFileLength); *h~(LH"tN
// fileSplitterFetch[nPos.length-1].start(); S%7%@Qs"%
g?9%_&/})A
7VA6J-T
//等待子线程结束 |dqvv
//int count = 0; U/:x<Y$ tj
//是否结束while循环 C44*qiG.
boolean breakWhile = false; vW03nt86
'?b.t2
pjNH0mZ
while(!bStop) =ve, !
{ (^= Hq'D
write_nPos(); V5]:^=
Utility.sleep(500); B=hJ*;:p
breakWhile = true; *Bx'g| u
]|4mD3O
\?NT,t=3J
for(int i=0;i<nStartPos.length;i++) J.pe&1
{ -0:B2B
if(!fileSplitterFetch.bDownOver) ?r}!d2:dX
{ BXX1G
breakWhile = false; \:-N<[
break; Lz;E/a}s
} ?p!+s96
} ot.R Gpg%
if(breakWhile) l|K`'YS!<{
break; -QP&A >]7
&Qq4xn+J
*!x/ia9
//count++; me/ae{
//if(count>4) `-)Fx<e
// siteStop(); |cq%eN
} Z|a\rNv
d^jIsE`
/'0,cJnm
System.err.println("文件下载结束！"); >zWVM1\\j
} sTGe=}T8
catch(Exception e){e.printStackTrace ();} b{Kw.?85
} 9C)w'\u9+
z/t:gc.
YP vg(T
//获得文件长度 {cBLm/C
public long getFileSize() 2-M]!x)
{ 6Bfu89
int nFileLength = -1; Gg9NG`e6I
try{ Ig6>+Mw
URL url = new URL(siteInfoBean.getSSiteURL()); yD!V;?EnK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZW|VAn'>
httpConnection.setRequestProperty("User-Agent","NetFox"); O[fgn;@|
0yxMIX
4c=oAL
int responseCode=httpConnection.getResponseCode(); 3fJwj}wL
if(responseCode>=400) ^y"$k
{ N:@C% UW}
processErrorCode(responseCode); Cz_chK4
return -2; //-2 represent access is error md/Z[du:'
} ?$^qcpJCp
cnOk
jsvD[\P
String sHeader; \$h LhYz-
S:"t]gbF =
-zVa[&
for(int i=1;;i++) @kKmkVhu*
{ @.X}S"yr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :[N[D#/z
//Utility.log(in.readLine()); a".uS4x
sHeader=httpConnection.getHeaderFieldKey(i); .SdEhW15)
if(sHeader!=null) QPfS3%p`
{ :*!u\lV\
if(sHeader.equals("Content-Length")) )Oz( <vxw
{ ZCMB]bL-e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5Ffz^;i
break; O/\jkF
} Sn/~R|3XA7
} (K+TqJw
else ?Ib/}JST
break; R6Cm:4m}I
} E `)p,{T
} wDZFOx0#8
catch(IOException e){e.printStackTrace ();} 5@Q4[+5&_
catch(Exception e){e.printStackTrace ();} !DCJ2h%E[_
L/GM~*Xp(O
<5(8LMF
Utility.log(nFileLength); :u{0M&
c+G: bb%p
|7/B20
return nFileLength; @X/S h:
} 7-ba-[t#A
*ftJ(
E!VAA=
//保存下载信息（文件指针位置） "ngYh]Git$
private void write_nPos() ('uYA&9
{ fu=}E5ScK
try{ RQU5T 2,
output = new DataOutputStream(new FileOutputStream(tmpFile)); %i%Xi+{3
output.writeInt(nStartPos.length); .tN)H1.:B
for(int i=0;i<nStartPos.length;i++) ojVpw4y.
{ 0mj=\j
// output.writeLong(nPos); H8K<.RY
output.writeLong(fileSplitterFetch.nStartPos); :<&}/r
output.writeLong(fileSplitterFetch.nEndPos); ^l^_K)tw*
} #G.3a]p}"
output.close(); 5.[{PJ]bq
} pLzsL>6h
catch(IOException e){e.printStackTrace ();} vEzzdDwi6
catch(Exception e){e.printStackTrace ();} `z` `d*_
} !icpfxOpjQ
]QT0sGl
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//读取保存的下载信息（文件指针位置） Z{p6Q1u
private void read_nPos() aG}9Z8D
{ f/;\/Q[Z7
try{ I I>2\d|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EkSTN
int nCount = input.readInt(); 4rM77Uw>
nStartPos = new long[nCount]; % C 3jxt
nEndPos = new long[nCount]; 38q@4U=aiw
for(int i=0;i<nStartPos.length;i++) N@MeaO
{ pXFNK"jm
nStartPos = input.readLong(); qfSoF|
nEndPos = input.readLong(); FOk @W&
} k)v[/#I
input.close(); )i_FU~ LRq
} Ix"c<1I
catch(IOException e){e.printStackTrace ();} K%=n \Y
catch(Exception e){e.printStackTrace ();} lIFt/
} Ab2g),;c
uAvs
H;sQ]:.*]
private void processErrorCode(int nErrorCode) u\e#_*>
{ ImV54h'
System.err.println("Error Code : " + nErrorCode); =H,cwSE+%
} Ar<OP'C
Ox~'w0c,f
~o/^=:*
//停止文件下载 Yip9K[
public void siteStop() Q?a"uei[
{ #h3+T*5} 6
bStop = true; d(@A
for(int i=0;i<nStartPos.length;i++) tJwF h6
fileSplitterFetch.splitterStop(); L\Jl'r|
r0X2cc
\4j+pU
} 7%E1F)%
} :>X7(&j8
//负责部分文件的抓取 jYy0^)6X(
**FileSplitterFetch.java "q`%d_
*/ ^X&9"x)4
package NetFox; 6gKOpa
87^ 4",
%UQ{'JW?K
import java.io.*; vfv5ex(
import java.net.*; Un/fP1
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xF/DYXC{8
public class FileSplitterFetch extends Thread { Q jBCkx]g
U2AGH2emw
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String sURL; //File URL 4jz]c"p-
long nStartPos; //File Snippet Start Position %f-<ol
long nEndPos; //File Snippet End Position >o} ati
int nThreadID; //Thread's ID V1:3
boolean bDownOver = false; //Downing is over >1~`tP
boolean bStop = false; //Stop identical W<LaR,7
FileAccessI fileAccessI = null; //File Access interface ?8,N4T0)
A pjqSz"
yo.SPd="Vx
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }}1/Ede{5
{ zrew:5*uZ
this.sURL = sURL; "?{yVu~9
this.nStartPos = nStart; ^d9raYE`'
this.nEndPos = nEnd; Dq?HUb^X
nThreadID = id; l1)pr{A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0w['jh|,
} lkZC?--H
]R{"=H'
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public void run() X{xJ*T y'
{ BNCJT$tYX
while(nStartPos < nEndPos && !bStop) qE72(#:R*
{ j_yFH#^W:
VQ?H:1R
8~)[d!'
try{ |2<f<k/UT
URL url = new URL(sURL); V3W85_*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _<a)\UR
httpConnection.setRequestProperty("User-Agent","NetFox"); #@6L|$iX
String sProperty = "bytes="+nStartPos+"-"; JX)z<Dz$
httpConnection.setRequestProperty("RANGE",sProperty); $JB:rozE
Utility.log(sProperty); G`#gV"PlC
d95N$n
\u_v7g
InputStream input = httpConnection.getInputStream(); ^X;Xti
//logResponseHead(httpConnection); 'B5J.Xe:
aF{i A\
gqD^Bs'VF
byte[] b = new byte[1024]; 4D8yb|o
int nRead; ]A]E)*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '(pdk
{ _ 1{5~
nStartPos += fileAccessI.write(b,0,nRead); OEE{JVeI
//if(nThreadID == 1) [E~,>Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z){UuiUM+=
} xnQGCw?S&}
SfobzX}~Jh
n{Qh8"
Utility.log("Thread " + nThreadID + " is over!"); sHTePEJ_h
bDownOver = true; Eb[H3v48,
//nPos = fileAccessI.write (b,0,nRead); Wx|6A#cg!
} _Q}RElA
catch(Exception e){e.printStackTrace ();} Z^`=!n-V
} ?*R^?[
} #Wm@&|U
a H|OA\<
cevV<Wy+
//打印回应的头信息 `{|}LFS>
public void logResponseHead(HttpURLConnection con) l&sO?P[ /
{ {.D2ON
for(int i=1;;i++) UE,~_hp
{ @j\?h$A/
String header=con.getHeaderFieldKey(i); fpK0MS]=b
if(header!=null) 1yaIV+_y/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <#p|z`N
Utility.log(header+" : "+con.getHeaderField(header)); dI ZTLb"a
else J]Gc
break; WQLHjGehe
} $|cp;~ 1
} .f !]@"\
ptWG@"j/b
]k`Fl,"
public void splitterStop() ;c m wh<
{ >.O*gv/_
bStop = true; +ptF-
} \;B$hT7z*
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w-'D*dOi
} V:F+HMBk
CVGOX z
]EVe@
/* 5<)gCHa
**FileAccess.java <(bCz>o|
*//文件访问(定位，写) PK2Rj%
package NetFox; j""y2c1
import java.io.*; UE&C
o! 2n}C
Q/3tg
public class FileAccessI implements Serializable{ fNAo$O4cm
0?6If+AC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X#p o|,Q
RandomAccessFile oSavedFile; 47C(\\
long nPos; Rg8m4xw
[V2omSZo
gI^L 9jE7
public FileAccessI() throws IOException ^EC)~HP@C
{ rF8W(E_=
this("",0); 409x!d~it
} l`v +sV^1
+#-kIaU
R8=I)I-8
public FileAccessI(String sName,long nPos) throws IOException +gbX}jF0%
{ ^)9MzD^_nV
oSavedFile = new RandomAccessFile(sName,"rw"); >/!7i3Ow-
this.nPos = nPos; h V|v6 _
oSavedFile.seek(nPos); WA]%,6
} j.=UI-&m
H})Dcg3
Q SHx]*)
public synchronized int write(byte[] b,int nStart,int nLen) ( Lok
{ ,>bGbx
int n = -1; SE,o7_k'S
try{ .%x"t>]
oSavedFile.write(b,nStart,nLen); iA55yT+
n = nLen; F,p`-m[q
} b(PHZCy#
catch(IOException e) H4PbO/{xO
{ [K/O5_
e.printStackTrace (); p3M#XC_H]
} 4 [R8(U[g
a,/M'^YyN
a)3O? Y
return n; B`?N,N"
} o}9M`[
]&Y#)ebs
u @{E{
} ~t'#nV
zY7*[!c2
ioB|*D<U2
/* U0NOU#
**SiteInfoBean.java fH{9]TU_:
*/ +3M$3w{2
package NetFox; OOEV-=
Q0pC4WJ`
NoFs-GGGh
public class SiteInfoBean { 1a7!4)\
Yw6DJY
I#"t'=9H
private String sSiteURL; //Site's URL *)MX%`Z}
private String sFilePath; //Saved File's Path >;&Gz-lm
private String sFileName; //Saved File's Name H7{Q@D8
private int nSplitter; //Count of Splited Downloading File `^v4zWDK
U8CWz!;Qz
G 6Wx3~
public SiteInfoBean() RY9+ 9i
{//nSplitter的缺省值为5 xj0cgK|!
//default value of nSplitter is 5 q>^hoW2$C
this("","","",5); FhWmO
} 1|o$X
Dc5bkm
<A)+|Y"^h6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .qSBh hH\
{ -G8c5b[
sSiteURL= sURL; {*N^C@
sFilePath = sPath; wb]*u7G t/
sFileName = sName; u K'<xM"%T
this.nSplitter = nSpiltter; i\(\MzW*'
J#0GlK@"
CXTt(-FT
} #MUiL=
>Z *iE"9"
rFhW^fP/
public String getSSiteURL() 8O;Vl
{ w|=gSC-o
return sSiteURL; 1 ojhh7<
} +W6Hva.
HeCcF+
\@i=)dA
public void setSSiteURL(String value) ]$3+[9x'
{ ^Z2kq2}a
sSiteURL = value; NjbwGcH%\
} 5|{)Z]M%9
wa" uFW
kGm:VYf%
public String getSFilePath() -&imjy<
{ K'NcTw#f
return sFilePath; CD}Ns
} BjiYv}J
Tj`yJ!0
gA_krK,Z
public void setSFilePath(String value) s|Zx(.EP
{ Uh.Sc:trA
sFilePath = value; [G a~%m
} $&IpX M]
,>u=gA&}
\83sSw
public String getSFileName() @;m$ua*|:
{ uArR\k(
return sFileName; 84'?um
} a\pi(9R
('t kZt%8
j5\$[-';
public void setSFileName(String value) -l "U"U"F
{ !qA8Zky_
sFileName = value; A:eG5K}
} NhA#bn9y?
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gLIT;BK
public int getNSplitter() 6Nt$ZYS
{ H0a-(
return nSplitter; 6^;^rUlm
} m"Qq{p|'
&x0C4Kh
PKA }zZ
public void setNSplitter(int nCount) $}R$t-
{ 5lTD]d
nSplitter = nCount; Q2/.6O8
} tWY2o3j
} ''S&e
Ax!Gu$K2o
xQu eE{
/* xMI+5b8
**Utility.java ,+._;[k
*/ ni6r{eSQ
package NetFox; =Ikg.jYq&F
\cQ .|S
u,7zFg)H
public class Utility { vG Vd
\DA$6w\\
!gH9ay
public Utility() 1pP1d%
{ @(:v_l
j'GtgT
8$vK5Dnn8
} <y)E>Fl
&Y7C0v
//线程睡眠 f vLC_'M
public static void sleep(int nSecond) '{f=hE_/
{ WM,i:P)b
try{ (][LQ6Pc
Thread.sleep(nSecond); b2kWjg.4
} N[Sb#w`[/
catch(Exception e) 5PZN^\^
{ 4tXSYHd3
e.printStackTrace (); [pgZbOIN37
} DjHp+TyT
} u3ZCT" !
B@t'U=@7
//日志 (~s|=Hxq|-
public static void log(String sMsg) ]Kdet"+
{ 8o-bd_
System.err.println(sMsg); w([$@1]
} g4&jo_3:p
;(6P6@+o
-<N&0F4|*
public static void log(int sMsg) x&=9P e(
{ *t9eZ!_f?
System.err.println(sMsg); |(% u}V?
} 27 GhE
} wW`}VKu
$Ui&D I
2KI!af[I
/* z4M1D9iPY
**TestMethod.java 3HiFISA*
*/ .T.5TMiOSq
package NetFox; G&9#*<F$c
or_+2aG
w1|Hy2D`0
public class TestMethod { . (`3JQ2s
3Wx,oq;4-
y,m2(V
public TestMethod() sR_xe}-
{ ///xx/weblogic60b2_win.exe Imym+
try{ w+AuMc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;Zut@z4\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vRhnX
SiteFileFetch fileFetch = new SiteFileFetch(bean); >+9JD%]x]
fileFetch.start(); =-jD~rN4;P
} p1O6+hRio
catch(Exception e){e.printStackTrace ();} wH6u5*$p
<GIwRVCU
jqcz\n d
} Utt>H@t[
,x_Z JL
4j'd3WGpbN
public static void main(String[] args) %mI~ =^za
{ {aj/HFLNY
new TestMethod(); 8^yJqAXK
} H;KDZO9W
} xJ(:m<z
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