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)); Mqtp}<*@-
} +r!h*4
for(int i=0;i<nEndPos.length-1;i++) ?W|IC8~d')
{ fDqXM;a"
nEndPos = nStartPos[i+1]; =GVhAzD3
} Xbtv}g<0c
nEndPos[nEndPos.length-1] = nFileLength; (}}8DB
} -d3y!|\>a
} |\(/dXXP
%UJ4wm
)x7hhEk=^
//启动子线程 *vO'Z &
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oX4uRc7wR
for(int i=0;i<nStartPos.length;i++) GKtQ>39B
{ 5#o,]tP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /_a *C.a6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L-R}O 8
nStartPos,nEndPos,i); ] zY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WO9/rF_
fileSplitterFetch.start(); bC{8yV=)
} :Y3?,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m'B6qy!}6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MX0B$yc$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T!a[@,)_
nEndPos = " + nFileLength); RGLA}|
// fileSplitterFetch[nPos.length-1].start(); RHbp:Mlk
R*0F)M
6v#G'M#r
//等待子线程结束 !v L:P2
//int count = 0; `@D4?8_
//是否结束while循环 !gf3%!%
boolean breakWhile = false; UVJ(iNK"
urB3
[alXD_
while(!bStop) 0cUt"(]
{ ~m?~eJK#a
write_nPos(); K-u/q6ufK
Utility.sleep(500); B,Brmn
breakWhile = true; ?$c
5UjQLB
kwR@oVR^
for(int i=0;i<nStartPos.length;i++) vNSf:5H$
{ z0[ZO1Fo(
if(!fileSplitterFetch.bDownOver) >2 qP
{ RWo B7{G
breakWhile = false; B-|Zo_7
break; UYOn p7R<
} [1^wy#
} Vb9N~v
if(breakWhile) RAI&;"
break; b1]_e'jj
3rg^R"&
5z ^UQq
//count++; 9%14k
//if(count>4) x 4</\o
// siteStop(); F5MPy[
} 34kd|!e,
[B @j@&
l|em E ^
System.err.println("文件下载结束！"); \q'fB?bS^
} Z;\"pP:
catch(Exception e){e.printStackTrace ();} 6ya87H'e@
} WUS9zK
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E_1I|$
//获得文件长度 AuipK*&g
public long getFileSize() H<}eoU.
{ :&)/vq
int nFileLength = -1; ld}$Tsy0
try{ {dXBXC/Ju
URL url = new URL(siteInfoBean.getSSiteURL()); mS}x2&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `j}d=zZ
httpConnection.setRequestProperty("User-Agent","NetFox"); b|o!&9Yyr
!o':\hex6
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int responseCode=httpConnection.getResponseCode(); lY*]&8/=
if(responseCode>=400) O:tX0<6
{ rOb"S*
processErrorCode(responseCode); :yjK*"T|OD
return -2; //-2 represent access is error F(~_L.
} /&as)
*/y]!<\v!k
fbTw6Fde$
String sHeader; Wx)U<:^e
fR%1FXpK&
2U`W[
for(int i=1;;i++) hUvuq,LH_
{ >-5Gt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 65#:2,s
//Utility.log(in.readLine()); ?VP!1O=J
sHeader=httpConnection.getHeaderFieldKey(i); !LOors za
if(sHeader!=null) OrEuQ-,i@
{ bTQa'y`3
if(sHeader.equals("Content-Length")) g+ 1=5g
{ /:{_|P\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); auTTvJ
break; 56SS >b
} f H|QAMfOu
} =Z .V+4+
else i(yAmo9h
break; qJXsf M6
} J7wQ=!g
} F0'A/T'ht
catch(IOException e){e.printStackTrace ();} 9Jy2T/l
catch(Exception e){e.printStackTrace ();} ViwpyC'v
@U3foL2\
k;_KKvQ
Utility.log(nFileLength); ,o@~OTja*
-F+P;S
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return nFileLength; ~K-*q{6Q
} tG2OVRx8u
Jp3di&x
&M3ES}6
//保存下载信息（文件指针位置） YG 5Z8@kH
private void write_nPos() 0SYf<$
{ Q|= Q]$d
try{ G9n /S=R?
output = new DataOutputStream(new FileOutputStream(tmpFile)); w-H%B`/
output.writeInt(nStartPos.length); LX\*4[0%K
for(int i=0;i<nStartPos.length;i++) C7 ]DJn
{ F\=Rm
// output.writeLong(nPos); Ep\
output.writeLong(fileSplitterFetch.nStartPos); fHe0W
output.writeLong(fileSplitterFetch.nEndPos); FL#g9U>
} (ND5CKCR^
output.close(); r3H}*Wpf
} Ur([L&
catch(IOException e){e.printStackTrace ();} k'ZUBTRq!
catch(Exception e){e.printStackTrace ();} 3_\{[_W
} 2@3.xG
}x?H ~QQT
1KYbL8c
//读取保存的下载信息（文件指针位置） p37zz4
private void read_nPos() ,]uX:h-EM
{ MO~~=]Y'
try{ ..]*Ao2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +eBMn(7Cgv
int nCount = input.readInt(); A!ioji+{[
nStartPos = new long[nCount]; JU'WiR bcb
nEndPos = new long[nCount]; &R'w-0k_
for(int i=0;i<nStartPos.length;i++) MjQ[^%lfL
{ N4a`8dS|
nStartPos = input.readLong(); Z#4JA/c!
nEndPos = input.readLong(); ~IlF*Zz#}6
} oI_oz0nHk
input.close(); -v;n"Zy1
} aJ6#=G61l
catch(IOException e){e.printStackTrace ();} s-C!uq
catch(Exception e){e.printStackTrace ();} cXk6e.Uz
} llHc=&y#
.Na&I)udX.
PG6[lHmi
private void processErrorCode(int nErrorCode) X(GmiH /E
{ C#Hcv*D
System.err.println("Error Code : " + nErrorCode); (!ZQ
} Ig1lol:;
1KTabj/C
@PPR$4
//停止文件下载 a{]g+tGH
public void siteStop() ]~ !XiCqu
{ *?_qE
bStop = true; cc|CC Zl
for(int i=0;i<nStartPos.length;i++) *.m{jgi1X
fileSplitterFetch.splitterStop(); Pqy-gWOv
N>d|A]zH
/~i.\^HX
} Ky[bX
} kqVg2#<@M
//负责部分文件的抓取 8^/+wa+G
**FileSplitterFetch.java [8F \;
*/ LkJ$aW/
package NetFox; T&1-eq>l
]urK$
2#z=zd
import java.io.*; ";PG%_(
import java.net.*; AH&9Nye8
>j50 ;</
|Du,UY/
public class FileSplitterFetch extends Thread { >vlQ|/C
r0F_;
RVc)") hQj
String sURL; //File URL Q0V^PDF
long nStartPos; //File Snippet Start Position 0jR){G9+
long nEndPos; //File Snippet End Position 5ZnSA9?
int nThreadID; //Thread's ID Y 3o^Euou
boolean bDownOver = false; //Downing is over $d'CBsu|<
boolean bStop = false; //Stop identical {]&R8?%
FileAccessI fileAccessI = null; //File Access interface JAc@S20v\
pO"m~mpA
`FUFK/7 w\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DVObrL)znL
{ S?*^>Y-e;
this.sURL = sURL; z*6$&sS\>
this.nStartPos = nStart; ZV!R#Xv
this.nEndPos = nEnd; "@.Z#d|Y
nThreadID = id; QTVa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |]^l^e6m
} R=`U4Ml;
0/ut:RV0
QT#b>xV)1
public void run() y0,Ft/D
{ #hIEEkCp +
while(nStartPos < nEndPos && !bStop) &oA~ Tx
{ k_]\(myq
7egq4gN]2Y
lZ}P{d'f.
try{ !q!"UMiG
URL url = new URL(sURL); ,# ]+HS^B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r+o_t2_b*
httpConnection.setRequestProperty("User-Agent","NetFox"); X*0k>j
String sProperty = "bytes="+nStartPos+"-"; 4Mk8Cpz
httpConnection.setRequestProperty("RANGE",sProperty); Y|mW.
Utility.log(sProperty); MzcB3pi
x'@W=P 7
^>-+@+( r
InputStream input = httpConnection.getInputStream(); iwUv`>l&
//logResponseHead(httpConnection); PmHd9^C
aZ$/<|y~:_
FIH@2zA
byte[] b = new byte[1024]; C?,*U
int nRead; M3ZOk<O<R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TZe+<~4*i%
{ wY/bA}%
nStartPos += fileAccessI.write(b,0,nRead); d$}&nV/A)
//if(nThreadID == 1) sTiYf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q*gnAi&.#
} oWI!u 5
(}G!np
Ddb-@YD&+0
Utility.log("Thread " + nThreadID + " is over!"); 4iwf\#
bDownOver = true; v{r1E]rY
//nPos = fileAccessI.write (b,0,nRead); |7y6 pz
} [~COYjp
catch(Exception e){e.printStackTrace ();} d [r-k 2
} J<rlz5':
} :i.t)ES
f_rp<R>Uu
Wj&nUp{
//打印回应的头信息 $|k%@Q>
public void logResponseHead(HttpURLConnection con) l_6eI
{ z?)He)d
for(int i=1;;i++) ^CUSlnB\(
{ )#a7'Ba
String header=con.getHeaderFieldKey(i); }B`Ku5 M
if(header!=null) *,17x`1e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t ^m~
Utility.log(header+" : "+con.getHeaderField(header)); >Co)2d]
else "CMucK
break; opXDm\
} "e@n:N!
} 7{4w2)
%yfE7UPS]
Y3k[~A7X
public void splitterStop() e gI&epN
{ L"^OdpOs
bStop = true; k=`$6(>Fz
} "CBRPp
}-74f
:> SLQ[1
} FI$XSG
grspt}
t{zBC?cR
/* *jE;9^
**FileAccess.java ->h5T%sn
*//文件访问(定位，写) h,t:]
package NetFox; P3!Atnv2
import java.io.*; q6REh;$
CcY7$D
w.z<60%},0
public class FileAccessI implements Serializable{ ~@D/A/|
A@2Bs5F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5rloK"
RandomAccessFile oSavedFile; RJhK$\
long nPos; ?`H[u7*%
P#MK
et` 0Je
public FileAccessI() throws IOException QD$Gw-U-l=
{ FAw1o
this("",0); <: :VCA%
} $Asr`Q1i
g5Hr7Km
/OG zt
public FileAccessI(String sName,long nPos) throws IOException R&*@@F-dx
{ {n&Uf{
oSavedFile = new RandomAccessFile(sName,"rw"); dxCPV6 XI
this.nPos = nPos; H O*YBL
oSavedFile.seek(nPos); Ys3uPs
} 35_)3R)
e>AXXUEf
|@wyC0k!
public synchronized int write(byte[] b,int nStart,int nLen) f@d9Hqr+l;
{ yQ%"U^.m
int n = -1; Us=eq "eu
try{ `eR 7H>I
oSavedFile.write(b,nStart,nLen); I3(d<+M
n = nLen; !),t"Ae?>
} oL-2qtv
catch(IOException e) psUE!~9,
{ nZ E)_
e.printStackTrace (); %j5ywr:
} to>
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return n; `N'V#)Pi
} (`c G
:h*a rT4{
<#*.}w~
} 3{ "O,h
wd+K`I/v7h
I 8zG~L%"
/* u-:Ic.ZV
**SiteInfoBean.java }`_(<H
*/ cP rwW6
package NetFox; vFhz!P~
e.8$ga{
y vI<4F
public class SiteInfoBean { :FHA]oec1
Ej"u1F14J
B(,:haAr
private String sSiteURL; //Site's URL ue\t,*KYd
private String sFilePath; //Saved File's Path |`0n"x7
private String sFileName; //Saved File's Name pW|u P8#
private int nSplitter; //Count of Splited Downloading File tTuX\;G
|]sx+NlNc
{dzoEM[ 1s
public SiteInfoBean() =;ICa~`C;
{//nSplitter的缺省值为5 3+U]?7t
//default value of nSplitter is 5 >cgpajx*
this("","","",5); =w%Oa<
} ej^3YNh&
efOjTA%
k\aK?(.RC7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ahGT4d`)9
{ Ia4)uV8
sSiteURL= sURL; #fDs[
sFilePath = sPath; *C2R`gpBI
sFileName = sName; {HrZ4xQnpV
this.nSplitter = nSpiltter; q>s`uFRg(
27#5y_ `
D$q'FZH
} RN9;kB)c
:L:&t,X
:dwt1>
public String getSSiteURL() :Li/=>R^
{ r:g9Z_
return sSiteURL; +ts0^;QO2{
} ue{xnjw>U
,={t8lN
{' 5qv@3
public void setSSiteURL(String value) m;,xmEp
{ $kPHxD!"
sSiteURL = value; ^3~e/PKM
} ^?GmrHC)
]l;*$2w)
1[PMDS_X
public String getSFilePath() a`c:`v2o
{ z&}-8JykH
return sFilePath; go'j/4Tp
} /'wF2UR
:dnJY%/q
T@YGB]*Y
public void setSFilePath(String value) h{'t5&yY
{ }NCL>l;q
sFilePath = value; /aqEJGG>
} +%0z`E\?M#
bS!\#f%9"
K5 KyG
public String getSFileName() ,6"l(]0
{ 8e2?tmWM
return sFileName; U[\Vj_?(I
} z5 m>H;P
>n*\bXf
J/x2qQ$9
public void setSFileName(String value) N4!<Xj
{ [f{VIE*?%
sFileName = value; 4. qtp`
} I;MD>%[W,
fiDl8=~@
V5mTu)tp5
public int getNSplitter() /-M@[p&
{ ,kM)7!]N
return nSplitter; '%;\YD9
} #x@eDnb_
=Lp7{09u
27Emm c
public void setNSplitter(int nCount) ccJM>9
{ [\e@_vY@OH
nSplitter = nCount; EbQa?
} z\!K<d"Xv
} X[3}?,aqL
Ip *g'
wdas1
/* cj$6
**Utility.java }}{Yw
*/ H=^K@Ti:
package NetFox; <V&5P3)d9
Ey`h1Y
Gc,_v3\
public class Utility { K|r Lkl9
5/0j}_pP
1DJekiWf
public Utility() (p)!Mq "^
{ )A8v];.]3
`BXS)xj
hZ$t$3
} dp5cDF}l
ku&k'V
//线程睡眠 HIvZQQW|
public static void sleep(int nSecond) j}JZ
{ q6d~V]4:
try{ _e<o7Y@_
Thread.sleep(nSecond); T6BFX0$
} A#y@`}]!'
catch(Exception e) n6Z|Q@F
{ Y3U9:VB
e.printStackTrace (); +cu^%CXT
} k!L@GQ
} \?fIt?
} p:%[
//日志 6" B%)0
public static void log(String sMsg) 5<YzalNf
{ V9%aBkf8w
System.err.println(sMsg); ?&+9WJ<M
} o^p
M[]A2'fS
5"KlRuv%
public static void log(int sMsg) 2umv|]n+l|
{ v3[@1FQ"
System.err.println(sMsg); TLa]O1=Bf.
} o*S"KX$
} Tl("IhkC
>bo'Y9C
_GYMPq\%L#
/* wIvo"|%
**TestMethod.java Vm1-C<V9
*/ % ZU/x d
package NetFox; 0#p/A^\#7M
e]8,:Gd(
Am4lEvb
public class TestMethod { 6sfwlT
5g5'@vMN
umEVy*hc
public TestMethod() va)%et0!
{ ///xx/weblogic60b2_win.exe n~IVNB*
try{ 1OaXo!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W8WXY_yJt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (8a#\Y[b
SiteFileFetch fileFetch = new SiteFileFetch(bean); B9dt=j3j2
fileFetch.start(); 1 jb/o5n;
} F\JUx L@8
catch(Exception e){e.printStackTrace ();} K95;rd
MjL)IgT
}?@5W,
} e&<yX
0ezYdS~o
{Tp2H_EG
public static void main(String[] args) +>f<EPGn
{ Q9F)
new TestMethod(); W&Y"K)`
} VyLH"cCv
} (=x"Y{%
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