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)); ==gL!e{
} mdQe)>
for(int i=0;i<nEndPos.length-1;i++) xpCZlOld
{ _~{J."q
nEndPos = nStartPos[i+1]; P;-.\VRu
} 2VUN
nEndPos[nEndPos.length-1] = nFileLength; r%WHYhD
} Oo-4WqRJ
} tQYV4h\Qj
l_$>$d
0I:5}$+J?
//启动子线程 zUDXkG*Lv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Qds:*]vGS
for(int i=0;i<nStartPos.length;i++) +?ZP3vgGA
{ B0Ay
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Mw"[2PA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8a]g>g
nStartPos,nEndPos,i); 6J#R1.h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q*,HN(&l?
fileSplitterFetch.start(); #H<}xC2
} LAM{ ,?~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `B&=ya|bl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :8`$BbV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N6p0`
nEndPos = " + nFileLength); |Kjfh};-C
// fileSplitterFetch[nPos.length-1].start(); 8B-mZFXpK
n7Bv~?DM
Cg%Owe/E?0
//等待子线程结束 ki}Li*)7
//int count = 0; Y~Vc|zM^(
//是否结束while循环 |pbetA4&
boolean breakWhile = false; _(~LXk^C
Y2tBFeWY
?u;m ],w!
while(!bStop) #@5VT*/7
{ .fhfb\$
write_nPos(); QVkji7)ZT
Utility.sleep(500); S.`hl/
breakWhile = true; z C$F@
t9*e"QH
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for(int i=0;i<nStartPos.length;i++) ]dl.~;3~~
{ "PWGtM:L8Y
if(!fileSplitterFetch.bDownOver) -P-8D6
{ 0u&x%c
breakWhile = false; RRYcg{g
break; ut]UU*g^$
} N!ay#V
} X2;72
if(breakWhile) m\CU,9;;(
break; 6R8>w,
:;hX$Qz
1Z;cb0:
//count++; fx4#R(N
//if(count>4) g:xg ~H2
// siteStop(); $%!06w#u
} <n2'm
b{)kup
Anpp`>}N
System.err.println("文件下载结束！"); 6I=xjgwvf
} . XbDb
catch(Exception e){e.printStackTrace ();} 8.^`~ta
} N?#L{Yt
Zn40NKYc
8''1H<f
//获得文件长度 E BoC,{R#
public long getFileSize() mA%}ijR6y
{ ,'t&L]
int nFileLength = -1; d8R|0RZ
try{ #*lDKn[vO
URL url = new URL(siteInfoBean.getSSiteURL()); q[W@.[2y)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uHbbPtk
httpConnection.setRequestProperty("User-Agent","NetFox"); VPuo!H
p\#;(pf}s
'rFLG+W
int responseCode=httpConnection.getResponseCode(); ]TUoXU2<x
if(responseCode>=400) /X0<2&v
{ lx0BKD?n
processErrorCode(responseCode); <^Y#q
return -2; //-2 represent access is error tn _\E/Q
} `s\[X-j]
kB5y}v.3 S
7h!nt=8Y
String sHeader; P s|[
/NR*<,c%
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for(int i=1;;i++) oa5L5Zr,A
{ jjv'"K2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F3$8l[O_
//Utility.log(in.readLine()); [; $:Lr
sHeader=httpConnection.getHeaderFieldKey(i); Mh3L(z]/E
if(sHeader!=null) |HJ`uGN<b
{ )k[XO
if(sHeader.equals("Content-Length")) `WxGU
{ N>sT@ > )
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); UUtSme
break; .wWf#bB
} qC& xuu|
} 4DP<)KX
else OI:=>Bk
break; 0$Zh4Y
} )@y'$)5s
} &gC)%*I4
catch(IOException e){e.printStackTrace ();} 0pB'^Q{
catch(Exception e){e.printStackTrace ();} P@n rcgM.
\k6OP
< 0S\P=\
Utility.log(nFileLength); 'u%_Ab_H
iWUxB28
2\O!vp>|-
return nFileLength; =*6frC~
} tBwPB#:W
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wa&:86~l?
//保存下载信息（文件指针位置） -cZuP7oA
private void write_nPos() -sle7k
{ zH~g5xgh
try{ c$u#U~~
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0lcwc"_DZX
output.writeInt(nStartPos.length); LS#_K-
for(int i=0;i<nStartPos.length;i++) #L*MMC"
{ [5M!'
// output.writeLong(nPos); VzcW9'"#
output.writeLong(fileSplitterFetch.nStartPos); /z)8k4
output.writeLong(fileSplitterFetch.nEndPos); ,g|ht%"
} U}=H1f,
output.close(); M3GFKWQI,`
} 6OQ\f,h@
catch(IOException e){e.printStackTrace ();} (f#{<^gd
catch(Exception e){e.printStackTrace ();} )^)|b5,
} ;D4 bxz0ou
Kl(u~/=6
~aL?{kb+
//读取保存的下载信息（文件指针位置） Hb^ovc0
private void read_nPos() mryT%zSlM
{ abEdZ)$
try{ z!~{3M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }y*rO(cu7G
int nCount = input.readInt(); ?iaO6HD
nStartPos = new long[nCount]; Na.e1A&?j
nEndPos = new long[nCount]; uIJ zz4
for(int i=0;i<nStartPos.length;i++) ?4Zo0DiUB
{ #X5Tt ;
nStartPos = input.readLong(); N$ 2Iz
nEndPos = input.readLong(); vDc&m
} ry* 9
input.close(); q'biTn]2
} 1gYvp9Ma
catch(IOException e){e.printStackTrace ();} :ZM=P3QZ
catch(Exception e){e.printStackTrace ();} @Hp=xC9V
} }k8&T\V!
wG22ffaki
oOQ0f |MGp
private void processErrorCode(int nErrorCode) ]ddL'>$c$
{ L'>0E(D
System.err.println("Error Code : " + nErrorCode); ^c sOXP=Yp
} Ftud6
IF?
pSpxd|k
//停止文件下载 #N\<(SD/
public void siteStop() #q?:Act
{ K*j1Fy:
bStop = true; O0mQHpi:
for(int i=0;i<nStartPos.length;i++) AAc2u^spx
fileSplitterFetch.splitterStop(); +2s][^-KV
&v+Hl^
cn_*,\}
} LQ"xm
} H.2aoZ-w
//负责部分文件的抓取 m W4tW
**FileSplitterFetch.java 6~8dMy;w
*/ @Z9>E+udQ
package NetFox; }iB>3|\
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` B+Pl6l)F
import java.io.*; Pj*"2 LBW#
import java.net.*; -9"[/
piPV&ytI
Jqt|'G3
public class FileSplitterFetch extends Thread { 8.' THLI
v%Su#xq/
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String sURL; //File URL 6uWPIM;
long nStartPos; //File Snippet Start Position #j"N5e}U
long nEndPos; //File Snippet End Position ^c>ROpic
int nThreadID; //Thread's ID ogE|8`Tq^
boolean bDownOver = false; //Downing is over Mj |"+(
boolean bStop = false; //Stop identical :DBJ2n
FileAccessI fileAccessI = null; //File Access interface %TQ5#{Y
{=E,.%8
!f8]gTzN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0 9*?'^s4
{ TJ(vq]|&
this.sURL = sURL; Hb9r.;r<EW
this.nStartPos = nStart; 'jU;.vZex
this.nEndPos = nEnd; v;R+{K87
nThreadID = id; 0 aiE0b9c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T7XbbU
} D4QLlP
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zLVk7u{e
public void run() :}fIu?hCA
{ DYL\=ya1
while(nStartPos < nEndPos && !bStop) &vS@-K
{ ",Fqpu&M
0kld77tn 2
VK$s+"
try{ n0'"/zyc
URL url = new URL(sURL); 0]t7(P"F6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dIvvJk8
httpConnection.setRequestProperty("User-Agent","NetFox"); 3=kw{r[2lM
String sProperty = "bytes="+nStartPos+"-"; vtf`+q
httpConnection.setRequestProperty("RANGE",sProperty); &0@AM_b
Utility.log(sProperty); ?rububDT{
nA XWbavY
@?<1~/sfL
InputStream input = httpConnection.getInputStream(); 7.1FRxS
//logResponseHead(httpConnection); )m$i``*<
C]%}L%,
o_%gFV[q
byte[] b = new byte[1024]; 'tzN.p1O
int nRead; q8fnUK?i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G!m;J8#m(
{ `v1~nNoY
nStartPos += fileAccessI.write(b,0,nRead); ndB*^nT
//if(nThreadID == 1) >U'gQS?\]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~px)Jd
} WzO[-csy
V]A*' ke/
;"DI)hdz
Utility.log("Thread " + nThreadID + " is over!"); &<S]=\
bDownOver = true; hvU\l`m
//nPos = fileAccessI.write (b,0,nRead); $3 ~/H"K
} !5h@uar
catch(Exception e){e.printStackTrace ();} I)cA:Ip
} PsoW:t
} Z <vTr6?
3gU*,K7
R//S(eU68\
//打印回应的头信息 &dI;o$t
public void logResponseHead(HttpURLConnection con) Y^J/jA0\B
{ ALnE[}N6,
for(int i=1;;i++) 5Lm<3:7Q+
{ 3r,^is
String header=con.getHeaderFieldKey(i); @ Yzj
if(header!=null) 91j.%#[v'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t_ZWd#x+;
Utility.log(header+" : "+con.getHeaderField(header)); RkXW(T`
else [^E{Yz=8,
break; `?xE-S ;Pn
} 5Gsjt+ o
} ^G]H9qY-e
SB2Ij',
e`D?x1-
public void splitterStop() /2e,,)4g
{ dW>$C_`?
bStop = true; s~MCt|a
} qz/d6-0"
K yFR;.F-
B< BS>(Nr>
} 14;lB.$p
|9cSG),z
/"OJ~e_%
/* 9\D0mjn=l
**FileAccess.java YO^iEI.
*//文件访问(定位，写) W0>fu>
package NetFox; )MJy
import java.io.*; ,}_uk]AQ
\Zms
~`Xu6+1o
public class FileAccessI implements Serializable{ #^oF^!
(qXl=e8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &C7HG^;W9
RandomAccessFile oSavedFile; b9@VD)J0E
long nPos; \H5{[ZUn
p?zh4:\F+
vAp?Zl?g
public FileAccessI() throws IOException uA2-&smw
{ f$^+;j
this("",0); [?Ub =sp
} j>t*k!db
-S%)2(f^
*<nfA}
public FileAccessI(String sName,long nPos) throws IOException 3teanU`
{ f.SmCgG
oSavedFile = new RandomAccessFile(sName,"rw"); =3?"s(9
this.nPos = nPos; =c(3EI'w
oSavedFile.seek(nPos); Kp_^ 2V?
} fnm:Wa|,%|
IB+)2`
C2 ] x
public synchronized int write(byte[] b,int nStart,int nLen) >E3 lY/[
{ <<[hZ$.
int n = -1; :},/D*v
try{ .JkF{&=B
oSavedFile.write(b,nStart,nLen); |]9Z#lv+I
n = nLen; =q-HR+
} ,"W.A
catch(IOException e) X}gnO83
{ 4C{3>BE
e.printStackTrace (); edy6WzxBcm
} oPA [vY
fCxF3m(O
*PVv=SU
return n; kGX;x}q
} ]\t+zF>&Y
{Qla4U
#Qp.O@e
} P7iU_CgyW
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eZWR)+aq
/* @j Y_^8#S
**SiteInfoBean.java W^^}-9
*/ WaRYrTDv64
package NetFox; 1"82JN|!
Z/ypWoV(
_("&jfn
public class SiteInfoBean { ?w[M{
YQ+Kl[ec
`b{.K,
private String sSiteURL; //Site's URL $q6'VLPo
private String sFilePath; //Saved File's Path s*B-|
private String sFileName; //Saved File's Name Kc:} Ky
private int nSplitter; //Count of Splited Downloading File bu2'JIDR
t[ZumQ@HC
!F|iL
public SiteInfoBean() k5@_8Rc
{//nSplitter的缺省值为5 dIR6dI
//default value of nSplitter is 5 =abth6#)
this("","","",5); )*Qa9+:
} d^w*!<8
Xkv+"F=-
Qb|.;_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CXsi
{ h8yv:}XU*
sSiteURL= sURL; .ZxH#l _
sFilePath = sPath; 6GD Uo}.
sFileName = sName; S0ct;CS
this.nSplitter = nSpiltter; Y{8L ~U:
^8V cm*
U&|$B|[
} PUN.nt
D=fB&7%@
fV;&)7d&
public String getSSiteURL() LEJ7.82
{ E5%ae (M^
return sSiteURL; d.7Xvx0Yww
} p ?HODwZ
ibOXh U
,QpDz{8
public void setSSiteURL(String value) d\ &jl`8*
{ +(3PY e\
sSiteURL = value; |7CH
} JAA P5ur
_]=`F l
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public String getSFilePath() N[$(y} !s
{ T_}\
return sFilePath; vR?L/G^.
} Z6b3gV
X |f'e@
.~5cNu'#m
public void setSFilePath(String value) K6,5C0
{ b'N"?W^YQ
sFilePath = value; aNW&ib
} P-~Avb
*TuoC5
azB~>#H~
public String getSFileName() n^/,>7J
{ qvOBvUR}
return sFileName; ``kKi3TWJ
} r)mm8MI!Z
)N-+,Ms
q\[31$i$
public void setSFileName(String value) w9}I*Nra
{ Y54*mn
sFileName = value; v]*W*;
} uF T\a=
$ZDh8 *ND
,>(M5\Z/c
public int getNSplitter() H[x9 7r
{ ji(S ?^
return nSplitter; D0QXvrf
} t:M({|m Y
sI`i
#k=!>%+E
public void setNSplitter(int nCount) E"Xi
{ :;"3k64
nSplitter = nCount; ,`|KNw5
} d*3R0Q|#{
} ?=IbiT
-T{~m6
gr=ke #
/* hJ:Hv.{`)W
**Utility.java O!f*@
*/ ]?)zH:2)
package NetFox; PJAir8
}qz58]fyx
;T52aX
public class Utility { .: 7h=neEW
7*XG]=z/
3F}d,aB A
public Utility() F{T|lTl
{ 9/s-|jD
8}\"LXRbo
6}ax~wYct
} uR"]w7=
+[2lS54"W4
//线程睡眠 00pHnNoxW
public static void sleep(int nSecond) 1shvHmrV
{ !#iP)"O
try{ hGus!p"lw
Thread.sleep(nSecond); db%`-UST
} P6=|C;[
catch(Exception e) >Ft jrEB
{ `ZefSmb
e.printStackTrace (); |J}~a8o
} 3\@6i'
} [1vrv(u>
NM]6 o
//日志 I3s}t$`y(
public static void log(String sMsg) 8'cDK[L
{ 3YT _GW{
System.err.println(sMsg); 'ZDa*9nkF
} eB]ZnJ2^=
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^$#Q_Y|
public static void log(int sMsg) ac&tpvij
{ 2=3iA09px
System.err.println(sMsg); L:^'cl} G
} E_yh9lk
} &FanD
?y04g u6p
:!A@B.E
/* z(%Zji@!N
**TestMethod.java W4YC5ZH{l
*/ krl yEAK=
package NetFox; >$"bwr}'4B
/cjf 1Dc
?)PcYrV
public class TestMethod { uw<Ruy
/n_HUY
Y.C*|p#
public TestMethod() LQQhn{[D
{ ///xx/weblogic60b2_win.exe ):[[Ch_
try{ $Y4 Ao-@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '",5Bu#C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0CN.gu
SiteFileFetch fileFetch = new SiteFileFetch(bean); W4|;JmT.r
fileFetch.start(); QWP_8$Q
} p{U8z\
catch(Exception e){e.printStackTrace ();} 9%dNktt
Z2@&4_P
QDDSJ>l5_T
} kB:R-St
eeX>SL5'i
0!zWXKX
public static void main(String[] args) 2Vi[qS^
{ Z3/zUtgs
new TestMethod(); }z*p2)v`
} R`<E3J\*
} @F1pu3E
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