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)); nh/%0=S
} _%PEv{H0.
for(int i=0;i<nEndPos.length-1;i++) "!PN+gB
{ QG;V\2T2[
nEndPos = nStartPos[i+1]; aByd,uSe)_
} R!RgQwEak
nEndPos[nEndPos.length-1] = nFileLength; 7JLjA\k
} |6Qn/N$+f
} " VSma
JP6+h>ft
e/<'HM T
//启动子线程 CVGQ<,KVW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -Dr)+Y
for(int i=0;i<nStartPos.length;i++) aq.Lnbi/X
{ g6;a2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2U'Vq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u 9kh@0
nStartPos,nEndPos,i); JS(%:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DG 6W ^
fileSplitterFetch.start(); HP[M"u
} $`|\aXd[C*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >8w=Vlp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GFYHt!&[\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UiN6-{v<2
nEndPos = " + nFileLength); sN@=Ri?\
// fileSplitterFetch[nPos.length-1].start(); ko`KAU<T_
SfGl*2
R9^RG-x
//等待子线程结束 `:fh$V5J>
//int count = 0; N=TDywRI
//是否结束while循环 `SG8w_
boolean breakWhile = false; QfI@=Kbg%#
HD8*>p.
Rj])c^ZA'*
while(!bStop) b("M8}o
{ je5GZFQw
write_nPos(); 2NZC,znQ
Utility.sleep(500); jmn<gJ2Of
breakWhile = true; #;s5=aH
pLsWy&G
pXoT@[}
for(int i=0;i<nStartPos.length;i++) n_P2l<F~/x
{ h0zv@,u
if(!fileSplitterFetch.bDownOver) &&`-A6`p
{ unAu8k^
breakWhile = false; /fC8jdp&
break; i-`J+8|d
} v|;}}ol
} g I@I.=y
if(breakWhile) 1\%2@NR
break; Kb*X2#;*
A%%Vyz
eBg:[44V
//count++; 71OQ?fc
//if(count>4) XjU/7Q
// siteStop(); 0yBiio
} }"6 PM)s
U6LENY+Ja
oaM3#QJ
System.err.println("文件下载结束！"); Yjh02wo
} =4:]V\o):'
catch(Exception e){e.printStackTrace ();} )o_Pnq9_
} 9{XV=a v
uN9J?j*ir
TX$4x~:
//获得文件长度 3s$vaV~(a
public long getFileSize() 9<-7AN}Z
{ L3'$"L.|u
int nFileLength = -1; Xx e07J~
try{ i6$q1*
URL url = new URL(siteInfoBean.getSSiteURL()); 6~!l7HqO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +$\/HO
httpConnection.setRequestProperty("User-Agent","NetFox"); noQS bI @
4ZrRgx2MD
h0;R*c
int responseCode=httpConnection.getResponseCode(); Hm 17El68
if(responseCode>=400) 0{!+N6MiR
{ @XN|R
processErrorCode(responseCode); M|}V6F_y
return -2; //-2 represent access is error L<[%tvV
} y5`$Aa4~
zL/rV<
(Kb_/
String sHeader; ECr}7R%
xpB*>zb
HAdDr!/`
for(int i=1;;i++) V~"-\@
{ ID8u&:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U\x$@J
//Utility.log(in.readLine()); 6QG"~>v7'(
sHeader=httpConnection.getHeaderFieldKey(i); WADAp\&
if(sHeader!=null) ){$*<#&H
{ S$ Z?T
if(sHeader.equals("Content-Length")) S)=3%toS>
{ VrnZrQj<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ktn:6=,
break; #-8%g{
} '0 J*9
} "-:-!1;Ji
else fOt?2Bh
break; Ln"D .gpq
} vMeB2r<
} ms`U,
catch(IOException e){e.printStackTrace ();} BL1d=%2R
catch(Exception e){e.printStackTrace ();} rIQ%X`Y
D/bF
,qT+Vqpr{
Utility.log(nFileLength); f yhBfA:u
K2!GpGZu
qw6i|JM%
return nFileLength; 't3&,:Y
} [K""6D
pI1IDu*_Z
s|!lw
//保存下载信息（文件指针位置） 1Ms_2
private void write_nPos() 8M8Odz\3 q
{ *IWWD\U
try{ 1w'W)x
output = new DataOutputStream(new FileOutputStream(tmpFile)); FqXE6^
output.writeInt(nStartPos.length); W=\45BJ
for(int i=0;i<nStartPos.length;i++) +D d!
{ A&D<}y/%
// output.writeLong(nPos); Czb:nyRj
output.writeLong(fileSplitterFetch.nStartPos); sMgRpem;
output.writeLong(fileSplitterFetch.nEndPos); BD?u|Fd,i:
} {wvBs87
output.close(); vC!B}~RG
} `CY c>n"
catch(IOException e){e.printStackTrace ();} ~'w]%rh!
catch(Exception e){e.printStackTrace ();} fxknfgbg
} UT_kw}1o
=buarxk
#MUY!
//读取保存的下载信息（文件指针位置） #T++5G
private void read_nPos() K8RV=3MBLD
{ l-$5CO
try{ =B0AG9Fz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U88gJ[$
int nCount = input.readInt(); 3@wio[
nStartPos = new long[nCount]; l4*vM
nEndPos = new long[nCount]; *=X61`0
for(int i=0;i<nStartPos.length;i++) 1'f&
{ !p!^[/9"c
nStartPos = input.readLong(); rUh2[z8:
nEndPos = input.readLong(); @K\hgaQ
} W<>R;~)
input.close(); W0XfU`
} QzS=oiL
catch(IOException e){e.printStackTrace ();} mjKu\7F
catch(Exception e){e.printStackTrace ();} @]7s`?
} $g_|U:,
m\G45%m
*R3^:Y&
private void processErrorCode(int nErrorCode) 1|:'jK#gE
{ /<1zzeHRSD
System.err.println("Error Code : " + nErrorCode); ca<OG;R^
} DdqE6qE
lP*p7Y '
Og7^7))
//停止文件下载 $},_O8R
public void siteStop() N"s"^}M\
{ Jw0I$W/
bStop = true; Zmm6&OZ%
for(int i=0;i<nStartPos.length;i++) eI98J"h%?
fileSplitterFetch.splitterStop(); @*BVS'\
IO7cRg'-F
lC@wCgc
} `*3;sq%`
} OV|n/~
//负责部分文件的抓取 s*R UYx
**FileSplitterFetch.java XbIxGL
*/ U#:N/ts*(
package NetFox; X 4\V4_
>dXB)yl
(L`IL e*
import java.io.*; UJ><B"
import java.net.*; o:`^1
`=%G&_3_<
8ib e#jlg
public class FileSplitterFetch extends Thread { |? rO
g%okYH?
>Se-5QtLcf
String sURL; //File URL |E&|6h1
long nStartPos; //File Snippet Start Position v%7Gh-P
long nEndPos; //File Snippet End Position ?(M$r\\
int nThreadID; //Thread's ID gfiFRwC`v
boolean bDownOver = false; //Downing is over `jec|i@oO
boolean bStop = false; //Stop identical u)vS,dzu
FileAccessI fileAccessI = null; //File Access interface IZuP{7p$
<Ok7-:OxA
}U?:al/m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o1thGttVDg
{ *onVG5<
this.sURL = sURL; ; W$.>*O
this.nStartPos = nStart; 9Zr6 KA{
this.nEndPos = nEnd; ;H9 W:_ahE
nThreadID = id; |XmzqX%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >0?ph<h1[q
} qv[w 1;U"
GJ:oUi
[8>#b_>
public void run() J;ycAF~
{ r`i.h ^2De
while(nStartPos < nEndPos && !bStop) 5%+epzy
{ =.l>Uw!
mR~S$6cc
JFq<sY!
try{ >7z(?nQYT^
URL url = new URL(sURL); n[\L6}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9'p*7o
httpConnection.setRequestProperty("User-Agent","NetFox"); S<z8
String sProperty = "bytes="+nStartPos+"-"; h6?o)Q>N
httpConnection.setRequestProperty("RANGE",sProperty); ),H1z`c&I
Utility.log(sProperty); E:;MI{;7
~MP/[,j`
EqOhzII^
InputStream input = httpConnection.getInputStream(); loUZD=Ph
//logResponseHead(httpConnection); *VaQ\]:d
+_jM$?:F}
3Xy~ap>Y
byte[] b = new byte[1024]; r@PVSH/
int nRead; ?;A\>sP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GK1P7Qy?V
{ =i6k[rg
nStartPos += fileAccessI.write(b,0,nRead); OS1f}<
//if(nThreadID == 1) _-2;!L#/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j+e s
} NTSIClm}U
qcge#S>
>8&fFq
Utility.log("Thread " + nThreadID + " is over!"); N*\ri0
bDownOver = true; l;@bs
//nPos = fileAccessI.write (b,0,nRead); kx;7/fH
} Q_dMuoI
catch(Exception e){e.printStackTrace ();} k%iwt]i%
} "whs?^/
} fcy4?SQ.<i
/N,\st
x6ayFq=
//打印回应的头信息 5Q:%f
public void logResponseHead(HttpURLConnection con) &da:{
{ 'j!n
for(int i=1;;i++) ]W5p\(1g
{ qpzyl~g:C
String header=con.getHeaderFieldKey(i); M!X^2
if(header!=null) (EH}lh}%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @z:E]O}
Utility.log(header+" : "+con.getHeaderField(header)); L uW""P/
else OzR<jCOS
break; 2`A[<S
} RL H!f1cta
} W$W w/mcl+
Fl*<N
70EH~
public void splitterStop() wOLV?Vk
{ "U$](k.<VA
bStop = true; `fl$ o6S/
} 3Bcv"O,B!{
X$?0C{@.}
d(9-T@J
} i 1Kq(7
\GKR(~f
1H-~+lf
/* 4J?\JcGs
**FileAccess.java /2MZH
*//文件访问(定位，写) 8~T=p:z'
package NetFox; tY:,9eh7B
import java.io.*; _xBhMu2f
K /%5\h
~Q5]?ZNX
public class FileAccessI implements Serializable{ 5Zmc3&vRl
TI\EkKu"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \rE] V,,2
RandomAccessFile oSavedFile; D(WV k
long nPos; 3{$>-d
NiQ Y3Nj
[ $"
public FileAccessI() throws IOException D *IeG>%
{ +;=>&XR0m
this("",0); keStK8
} f1?%p)C
wA6E7vi'
-B(p8YH
public FileAccessI(String sName,long nPos) throws IOException 1QnaZhu'
{ ):A.A,skf
oSavedFile = new RandomAccessFile(sName,"rw"); 7xR:\FBa^
this.nPos = nPos; ` k(Q:
oSavedFile.seek(nPos); nc1?c1s,f
} T0.sL9
e E(+
0QxBC7`qp
public synchronized int write(byte[] b,int nStart,int nLen) =@q,/FR-
{ UMT}2d%
int n = -1; B\l0kiNT
try{ zMM~4?4
oSavedFile.write(b,nStart,nLen); "KSdC8MS
n = nLen; U??OiKVZ+
} `:jF%3ks+0
catch(IOException e) e)}=T0 s
{ LabI5+g
e.printStackTrace (); k~F,n
} e2g`T{6M
[xQ.qZ[h&
9[lk=1.qN
return n; ^NM>xIenf
} F+j"bhe
B~J63Os/
@;KvUR/+FE
} Dz/MIx
BB ::zBg
ZwiXeD+4
/* <*P)"G
**SiteInfoBean.java .ud&$-[a
*/ xsNOjHk
package NetFox; mS49l
!DV0u)k(
N P5K1:
public class SiteInfoBean { .q!i +0
?FEh9l)d\
oq b(w+<
private String sSiteURL; //Site's URL B}K<L\S
private String sFilePath; //Saved File's Path J,s:CBCGL
private String sFileName; //Saved File's Name FMzG6nrdBN
private int nSplitter; //Count of Splited Downloading File J aJ/|N
e AaS }g 0
~-uDN)
public SiteInfoBean() '(ZT}N
{//nSplitter的缺省值为5 OYb:);o,iE
//default value of nSplitter is 5 |`fuu2W!
this("","","",5); ^t$uDQ[hA
} ;Cjj_9e,:
dxH.
y(E<MRd8V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MmFtG-
{ #&?}h)Jr'
sSiteURL= sURL; 4r86@^c*
sFilePath = sPath; _'^_9u G
sFileName = sName; 7Jz9%iP
this.nSplitter = nSpiltter; 2 gca*
:"b:uQ
Vn\jUEC
} 2^nws
][YuJUK8
{M=*>P]E
public String getSSiteURL() 7s;;2<k;_
{ L|;sB=$'{
return sSiteURL; ZF8`=D`:R
} FPPl^
rEbH<|
.'h^
public void setSSiteURL(String value) bQ&%6'ck
{ pd.unEWwF
sSiteURL = value; )h{+pK
} x|()f3{.
Md8<IFi9]Q
P8;1,?ou
public String getSFilePath() A]drNFE
{ +oHbAPs8
return sFilePath; ou`KkY||
} =)*ZrD
$D D esy3
/s+S\ djk
public void setSFilePath(String value) -"^xg"
{ rhly.f7N=A
sFilePath = value; ug;~dhe~
} ~&+a.@T
eZ0-O /_i
EB6X Yr
public String getSFileName() 7@m+y
{ }OTJ{eG
return sFileName; z2!4w +2
} SUW=-M
x3.,zfWs
j*;.>akY7
public void setSFileName(String value) \~t!M~H
{ TmM~uc7mj
sFileName = value; Q}a(vlZ
} Z%=A[`5]
5w+&plIJ
c~OvoTF,
public int getNSplitter() @D `j
{ H<P d&
return nSplitter; hb %F"Q
} @O-\s q
]1W]
"<%J^Z9G
public void setNSplitter(int nCount) U6y`:G;.
{ 1?.NJ<)F
nSplitter = nCount; zE?dQD^OD
} 9\=SG"e(
} cqW(9A|8
ZPz=\^
(hIo0.
/* 9wO2`e )
**Utility.java /NobS'd
*/ fL]jk1.Xv-
package NetFox; s<aG
|`V=hqe{
!$!%era`
public class Utility { `R-?+76?
U3UA
'#.D`9YI<
public Utility() tDfHO1pS
{ "V`DhOG&
-w5sXnS
Iek]/=
} I:YgKs)[
e#k)F.TZ:%
//线程睡眠 >l=^3B,j
public static void sleep(int nSecond) IY mkZ?cW
{ HS\'{4P
try{ A4b+:MQ*OX
Thread.sleep(nSecond); Nw-U*y
} dy'lM ;@-
catch(Exception e) `>)pqI%L[g
{ !;hp
e.printStackTrace (); x~{W(;`!
} N%1nii
} UdA,.C0
v$g\]QS p
//日志 sBqOcy
public static void log(String sMsg) VwK7\jV
{ Ai5+ ;8z+
System.err.println(sMsg); (NJ.\m
} wwJs_f\
j#Lj<jX!xR
FP*kA_z$
public static void log(int sMsg) FT-=^VA\
{ LB}J7yEQvj
System.err.println(sMsg); xe3Jxo!U
} !T8sWMY
} 1rLxF{,
#YK3Ogb,
d3#e7rQ8
/* {SRD\&J[
**TestMethod.java jR@>~t[}o
*/ $d,{I8d
package NetFox; s'IB{lJ9
l m(mY$B*_
>$=l;jO`n
public class TestMethod { xh!T,|IR
,Z! I^
C',uY7}<
public TestMethod() pr,1pqiAf
{ ///xx/weblogic60b2_win.exe /;E=)(w
try{ :_,3")-v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :C,}DyZy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -pQ?ybQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); zG^$-L.n
fileFetch.start(); 4%JJ}{Ff
} UQ@szE
catch(Exception e){e.printStackTrace ();} &0J8ICd=
pqju@FD*
D>Rlm,U
} '- #QK'p
G-sQL'L[U
7m?fvKy
public static void main(String[] args) jtE'T}!d
{ R4$(NNC+/
new TestMethod(); &yOl}?u
} T\:*+W37
} HYY+Fv5
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