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)); U?6YY`A8
} oK GFDl]3
for(int i=0;i<nEndPos.length-1;i++) p,=:Ff}~
{ "}bk *2
nEndPos = nStartPos[i+1]; $rySz7NI
} ^;2dZgJ4^
nEndPos[nEndPos.length-1] = nFileLength; G~{xTpL
} X^#.4:>.
} $FgpFxz;
.bOueB-
Cl;B%5yl
//启动子线程 dJ#. m
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @5%cP
for(int i=0;i<nStartPos.length;i++) !P, 9Sg&5)
{ / 4K*iq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EX[X|"r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j/bebR}X
nStartPos,nEndPos,i); sBuVm<H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g#V3u=I8~
fileSplitterFetch.start(); d0b--v/
} b&g9A{t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $ ;/Ny)"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &Z+a (
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )>ed6A1
nEndPos = " + nFileLength); [|2uu."$
// fileSplitterFetch[nPos.length-1].start(); HRx%m1H
BEM+FG
Z;@F.r
//等待子线程结束 Y.?|[x0Wh
//int count = 0; T[=XGAJ
//是否结束while循环 _9Kdcoh
boolean breakWhile = false; a$MMp=p
]t|KFk!)
FeS6>/
while(!bStop) -/aDq?<<
{ j=)%~@
write_nPos(); PZ-|W
Utility.sleep(500); i4.s_@2Y
breakWhile = true; S\Qh#yFT
=VlO53Hy{
/|y3M/;F
for(int i=0;i<nStartPos.length;i++) }[PbA4l.g
{ |,]#vcJP#b
if(!fileSplitterFetch.bDownOver) gU/\'~HG
{ "w`f>]YLA
breakWhile = false; >]=1~sF
break; #UC4l]Ru A
} fp9ksxb@m
} -9{}rE
if(breakWhile) y^zVb\"4
break; R,A|"Q
p]:~z|.Ba
?x@BZe
//count++; ~?aq=T
//if(count>4) |rf\]3 F
// siteStop(); gtz!T2%
} 5/mW:G,&
"HVwm>qEi
pi5Al)0
System.err.println("文件下载结束！"); SGH"m/ e
} IgC)YIhd
catch(Exception e){e.printStackTrace ();} 4(&00#Yxg2
} T}P|uP
,u(g#T
N7Z&_$Bx
//获得文件长度 1z~;c|
public long getFileSize() @l&5 |Cia
{ %yQ-~T@
int nFileLength = -1; *ZGQ`#1.X6
try{ x}1(okc
URL url = new URL(siteInfoBean.getSSiteURL()); )xP]rOT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~@z5Ld3xz
httpConnection.setRequestProperty("User-Agent","NetFox"); t9m:E
E[LXZh
P-No;/!B#
int responseCode=httpConnection.getResponseCode(); -z0,IYG }
if(responseCode>=400) [j}%&$
{ ~SZ0Yu:X
processErrorCode(responseCode); &}w,bG$
return -2; //-2 represent access is error Q=gVxS
} {Y'DUt5j
/Os)4yH\
622mNY
String sHeader; ,D3q8?j
u!nt0hS
"SyyOD )WA
for(int i=1;;i++) nH% /
{ g@nk0lQewj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); + 7E6U*
//Utility.log(in.readLine()); WLNkO^zb
sHeader=httpConnection.getHeaderFieldKey(i); +zs;>'Sf
if(sHeader!=null) SNff
{ Y!o@"Ct
if(sHeader.equals("Content-Length")) oLX6w
{ `M4;aN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MH"c=mL:
break; ClVMZ
} 43:~kCF[s
} Aid{PGDk
else ,i*^fpF`F"
break; &.<{c `-
} :!tQqy2
} HK&F'\'}
catch(IOException e){e.printStackTrace ();} =q[3/'2V$?
catch(Exception e){e.printStackTrace ();} wC=IN
K N0S$nW+
-mX _I{BJ
Utility.log(nFileLength); )l30~5u<J
=q5A@!D
G!OD7:
return nFileLength; w^`n
} |}q0G~l
d-N<VVcy\
])~*)I~Y
//保存下载信息（文件指针位置） 3QUe:8
private void write_nPos() D9H|]W~
{ <ze'o.c
try{ )CdglPK
output = new DataOutputStream(new FileOutputStream(tmpFile)); O:lD>A4{
output.writeInt(nStartPos.length); 6/@ cP/
for(int i=0;i<nStartPos.length;i++) +-ieaF
{ rIge6A>I
// output.writeLong(nPos); *i%!j/QDAP
output.writeLong(fileSplitterFetch.nStartPos); 348Bu7':
output.writeLong(fileSplitterFetch.nEndPos); do=VPqy
} ]X?+]9Fr
output.close(); |.(o4<nx.
} |nD2k,S<?
catch(IOException e){e.printStackTrace ();} {,s:vPoiA
catch(Exception e){e.printStackTrace ();} `2S{.s
} eIof{#
VWfrcSZg6M
mW8CqW\Q5
//读取保存的下载信息（文件指针位置） RNX}Wlo-s
private void read_nPos() :?RK>}4|F
{ S~Q7>oNm
try{ tinN$o Xy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =/dW5qy;*+
int nCount = input.readInt(); gdCU1D\
nStartPos = new long[nCount]; {_[l,tdZ
nEndPos = new long[nCount]; {b/AOR o
for(int i=0;i<nStartPos.length;i++) Z"!C
{ M"p$9t
nStartPos = input.readLong(); `$@1NL7>
nEndPos = input.readLong(); /~ V"v"7E
} #C>pA<YJzK
input.close(); 1uXtBk6
} TF=S \ Q
catch(IOException e){e.printStackTrace ();} JxD@y}ZYE
catch(Exception e){e.printStackTrace ();} 'Fc&"(!||
} $AsM 9D<BE
3\D jV2t
L9r 3jz
private void processErrorCode(int nErrorCode) 7ky(g'
{ 2s6Vy
System.err.println("Error Code : " + nErrorCode); S~6<'N&[
} pd7FU~-
>Q5 SJZ/
]E=JUYf0
//停止文件下载 oTx#e[8f{
public void siteStop() oY.JK
{ N(1jm F
bStop = true; L</"m[
for(int i=0;i<nStartPos.length;i++) gXw\_ue<
fileSplitterFetch.splitterStop(); AQ0L9?
&S|laqH
JHO9d:{-
} *Z/B\nb
} mup3ua]!
//负责部分文件的抓取 h{PLyWH
**FileSplitterFetch.java 8d$~wh
*/ *$l8H[
package NetFox; r2sog{R
IRS^F;)
1.>sG2*P
import java.io.*; YKM(qh2
import java.net.*; {L4^IKI
>nr1|2
{g )kT_
public class FileSplitterFetch extends Thread { g|r
`DA=';>Y
9L&AbmIr
String sURL; //File URL gJF;yW4
long nStartPos; //File Snippet Start Position BO h
long nEndPos; //File Snippet End Position 'GW@P
int nThreadID; //Thread's ID #x%O0
boolean bDownOver = false; //Downing is over {O^1WgGc[
boolean bStop = false; //Stop identical 5 !NPqka}.
FileAccessI fileAccessI = null; //File Access interface #bdJ]v.n
5Cz:$-+
~RMOEH.o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Gu_s:cgB9F
{ \h0e09& I
this.sURL = sURL; A6UtpyS*'
this.nStartPos = nStart; oFIs,[Go
this.nEndPos = nEnd; |x kixf4zz
nThreadID = id; 0cS.|\ZTA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vMC;5r6*d
} -#Wc@\;
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public void run() T%]: tDa
{ z$YOV"N
while(nStartPos < nEndPos && !bStop) RyM2CQg[
{ igo7F@_,
`zsKc 6%
.#Sd|C]R7
try{ 8;Pdd1GyUL
URL url = new URL(sURL); _@RW7iP>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cdGl[dQ/
httpConnection.setRequestProperty("User-Agent","NetFox"); ]kKsGch
String sProperty = "bytes="+nStartPos+"-"; mV4} -
httpConnection.setRequestProperty("RANGE",sProperty); W%$p,^@S5
Utility.log(sProperty); QR8F'7S
d5],O48A
Fvv6<E
InputStream input = httpConnection.getInputStream(); XSD7~X/:
//logResponseHead(httpConnection); 4a646jg)
[%h^qJ
i$NnHj|
byte[] b = new byte[1024]; jgO{DNe(=
int nRead; )O+9v}2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5GRN1Aov<
{ @rJ#Dr
nStartPos += fileAccessI.write(b,0,nRead); k~hL8ZT[
//if(nThreadID == 1) > voUh;L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z'fy9
} zf S<X
Cn{UzSKfs
HL!-4kN <$
Utility.log("Thread " + nThreadID + " is over!"); "xO`&a{
bDownOver = true; VtmUK$k}I
//nPos = fileAccessI.write (b,0,nRead); [ z&y]~
} :?^(&3;
catch(Exception e){e.printStackTrace ();} ~\kRW6
} ^1nf|Xj[
} WW_X:N~~e\
#".{i+3E
aY?}4Bx
//打印回应的头信息 P$oa6`%l
public void logResponseHead(HttpURLConnection con) oC?b]tzj
{ #?,cYh+
for(int i=1;;i++) ']rh0?
{ :@3d
String header=con.getHeaderFieldKey(i); "vJADQ4F
if(header!=null) 9\n}!{@i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8uu:e<PLv
Utility.log(header+" : "+con.getHeaderField(header)); >\i{,F=U7
else 0-#ct1-
break; ~/.&Z`ls
} Y}[r`}={
} Fd91Y
3&zmy'b*:
f2Slsl;
public void splitterStop() C[Fh^
{ ew0 )
bStop = true; U?rfE(!
} 2Hd6
8~I>t9Q+
h?O-13v
} :,u+[0-S
F 4hEfO3
9o18VJR
/* *%8us~w5/
**FileAccess.java iVl"H@m/
*//文件访问(定位，写) K~E]Fkw!;
package NetFox; Ue\&
import java.io.*; 2V0R|YUt
- Z|1@s&
H9nq.<;p
public class FileAccessI implements Serializable{ mB :lp=c`
(+U!#T]'D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xpnnWHdaq
RandomAccessFile oSavedFile; %NBD^gF
long nPos; ;L)}blN.
8[Qw8z5-
xv ja
public FileAccessI() throws IOException w_Ls.K5"
{ i a|F
this("",0); urN&."c
} 2<O hO ^
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'2vlfQ@8a~
public FileAccessI(String sName,long nPos) throws IOException &sllM
{ _]4cY%s
oSavedFile = new RandomAccessFile(sName,"rw"); WV6vM()#!C
this.nPos = nPos; ewLr+8
oSavedFile.seek(nPos); V?gQ`( ,
} [ wROIvV
emaNmpg
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public synchronized int write(byte[] b,int nStart,int nLen) J2R<'(
{ Ug"B/UUFd
int n = -1; l5MxJ>?4%B
try{ +:t1PV;l
oSavedFile.write(b,nStart,nLen); hb_Ia]b
n = nLen; RWoiV10
} x O)nS _I
catch(IOException e) 7}#vANm
{ Jk~T.p?tF
e.printStackTrace (); "pH+YqJ$
} eMF%!qUr
`b2I)xC#
j4l7Tx
return n; (I+-wki"e
} x|Ei_hI-
v|"{x&I.
=:2V4H(F
} B|%;(bM2C
qle\c[UM5
@fY!@xSf
/* /yOd]N;$
**SiteInfoBean.java pUPb+:^R
*/ <ya3|ycnS
package NetFox; *7R3EUUk
kSJWQ
fT@#S}t
public class SiteInfoBean { k`&mHSk-
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private String sSiteURL; //Site's URL Qh*|mW
private String sFilePath; //Saved File's Path OUs2)H61
private String sFileName; //Saved File's Name @#V{@@3$
private int nSplitter; //Count of Splited Downloading File X=JSqO6V9
OVd"'|&6_
=thgNMDm"
public SiteInfoBean() tQ)8HVKF
{//nSplitter的缺省值为5 e"bF"L
//default value of nSplitter is 5 -1{N#c/U
this("","","",5); 5|Y4GQVz
} p;p G@Vg
}Orc;_)r
k&**f_b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |%tR#!&[:g
{ n*;I2FV]
sSiteURL= sURL; _#L IG2d
sFilePath = sPath; 4@bL` L)
sFileName = sName; F|PYDC
this.nSplitter = nSpiltter; &o8\ $A
& =frt3
Q~]R#S
} 9xSAWKr,l
5~sJ$5<,
'UB<;6wy
public String getSSiteURL() eg}|%GG
{ 1xx-}AIH#
return sSiteURL; T.{I~_
} tVe*J@i\$
]y(#]Tw\
"16==tLFE
public void setSSiteURL(String value) sz)3 z
{ F;z FKvn
sSiteURL = value; D~1nh%x_
} ,og@}gOMB
bc&:v$EGy
O,bj_CWx
public String getSFilePath() 5!5P\o
{ :hevBBP
return sFilePath; }^QY<Cp|
} W=|B3}C?
c#l (~g$D+
Lb];P"2e+
public void setSFilePath(String value) IUZsLNW
{ :n>h[{o%
sFilePath = value; !g}9xIL
} !q/?t XM!
R sujKh/
7?A}qmv
public String getSFileName() 3wr~P
{ 8en85 pp8P
return sFileName; I*24%z9
} :H?p^d e
Z|~<B4#c
EatpORq
public void setSFileName(String value) *m|]c4
{ E]gKJVf9[
sFileName = value; *+J&ebSTN
} ,+q5e^P
r67 3+
plp).Gq
public int getNSplitter() N),Zb^~nw
{ Bz24U wcZ
return nSplitter; 7{b|+0W
} :Z/ig%
H\ NO4=
Kj-`ru
public void setNSplitter(int nCount) MjLyB^M
{ ?! kup
nSplitter = nCount; ` "9Y.KU
} !E*-\}[
} (C. 1'<]
#cApk
3FS:]|oC
/* ha(hG3C
**Utility.java HFf| >&c&
*/ ]])i"oew
package NetFox; *M8 4Dry`y
PCFm@S@Q
#}A!Bk
public class Utility { J"SAA0)@
}b0qrr
M r@M~ -
public Utility() #7g~Um%p
{ u{\`*dNx
S4tdWA
zKI(yC
} F 6SIhf.;
xxedezNko
//线程睡眠 kDm=Cjxv
public static void sleep(int nSecond) z~X]v["d
{ K7y}R%QF
try{ a#mdD:,cF
Thread.sleep(nSecond); bb#w]!q
} FS']3uJ/
catch(Exception e) ,@2O_O`:
{ 2 OGg`1XX
e.printStackTrace (); aUJ&
} .2u%;)S
} QXF>xZ~
'QkL%z0
//日志 ,;{mH]"s
public static void log(String sMsg) zZA I"\;W
{ @@! R Iq!
System.err.println(sMsg); 45_zO#
} (apAUIE
$YW z~^f
&18} u~M
public static void log(int sMsg) PAqziq.
{ NW~n+uk5v
System.err.println(sMsg); dz7*a{
} ]5} =r
} .kBAUkL:
8^HMK$
P+]39p{
/* {E@@14]g
**TestMethod.java b@,w/Uw[*
*/ !ZB|GLpo6
package NetFox; v1;`.PWD
mjH8q&szf
tFb49zbk
public class TestMethod { ";xG[ne$Be
J4x1qY)Y&v
56L>tP
public TestMethod() ?X=9@m
{ ///xx/weblogic60b2_win.exe $3FFb#r
try{ E|ZY2&J`4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /TpM#hkq/2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _~6AUwM
SiteFileFetch fileFetch = new SiteFileFetch(bean); in%+)`'nH7
fileFetch.start(); @P)GDB7A
} (z"Cwa@e
catch(Exception e){e.printStackTrace ();} >yT:eG
=WN6Fj`
JP[BSmhAV
} CjIkRa@!x
Prr<:q
a-O9[?G/x
public static void main(String[] args) \ar.(J
{ koaH31Q
new TestMethod(); 0xH$!?{b
} +DVU"d
} #p\sw
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