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)); +MZ2e^\F
} 'KW+Rr~tZn
for(int i=0;i<nEndPos.length-1;i++) 7u&H*e7
{ a7 '\*
nEndPos = nStartPos[i+1]; =fu_ Jau}
} _tg3%X]
nEndPos[nEndPos.length-1] = nFileLength; lfI7&d*
} ]T28q/B;k
} b^|,9en
?),K=E+=U
5D q{"@E
//启动子线程 r0XGGLFuZl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >=RHE@
for(int i=0;i<nStartPos.length;i++) ~A{[=v
{ K`AW?p^$Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^,\se9=(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H"Em|LX^
nStartPos,nEndPos,i); :fMM-?s]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [+[fD
fileSplitterFetch.start(); 7C6BZ$(
} %%-Tjw o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9"l%tq_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9ixnf=$Jp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G#=b6DB
nEndPos = " + nFileLength); S3[oA&
// fileSplitterFetch[nPos.length-1].start(); L:];[xa%
hF?\K^tF
e1Z;\U$&.
//等待子线程结束 #xE>]U
//int count = 0; s9)8{z
//是否结束while循环 hrtN.4p[
boolean breakWhile = false; %>QSeX
e[Ul"pMvS`
l=.InSuLT
while(!bStop) DyV[+P
{ (j\UoKLRt
write_nPos(); TTjjyZ@
Utility.sleep(500); Y{\2wU!Isn
breakWhile = true; m]b.P,~v
+r34\mAO
i_Q4bhVj
for(int i=0;i<nStartPos.length;i++) r'}k`A5>
{ P|QnZ){
if(!fileSplitterFetch.bDownOver) YJ;a{)e
{ _a02#
breakWhile = false; "q#g/T
break; yyYbB]D
} s</ktPtu
} iS^^Z ZyR
if(breakWhile) (5\d[||9g
break; /-} p7AM
/:];2P6#X
$[9V'K
//count++; PfMOc+ q
//if(count>4) t3kh]2t
// siteStop(); |x~ei_x7.p
} LB 5EGw
UmHb-uk ;
>Sl:Z ,g;
System.err.println("文件下载结束！"); Sv[_BP\^h
} XcW3IO
catch(Exception e){e.printStackTrace ();} Op)R3qt{
} o3`gx
5L'@WB|{4u
fxCPGj
//获得文件长度 5EZr"[8M
public long getFileSize() Pxuz {
{ N=}Z#
int nFileLength = -1; RyIaT
try{ 5nlyb,"^g
URL url = new URL(siteInfoBean.getSSiteURL()); "Kf~`0P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AZm)$@e)
httpConnection.setRequestProperty("User-Agent","NetFox"); oA^ ]x>
JL+[1=uE1L
)eVDp,.^
int responseCode=httpConnection.getResponseCode(); "g&l~N1$
if(responseCode>=400) 5+PBS)pJ]%
{ /VOST^z!
processErrorCode(responseCode); RAJ|#I1
return -2; //-2 represent access is error Kwmo)|7uPU
} ;bu;t#
'48|f`8$
eh# (}v
String sHeader; -cC(d$y
olW`.3f
_p^ "!
for(int i=1;;i++) w\[*_wQp
{ sJ*U Fm{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vG=$UUh@~
//Utility.log(in.readLine()); *`/@[S2,cu
sHeader=httpConnection.getHeaderFieldKey(i); gG|1$
if(sHeader!=null) 8c'-eT"
{ ~.=HN}E
if(sHeader.equals("Content-Length")) g0U\AN
{ Wam?(!{mOf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jywz27j
break; o%s}jBo}
} 246!\zf
} JaN_[ou
else hndRgCo
break; JHOBg{Wg
} mAERZ<I
} 6>^k9cJp
catch(IOException e){e.printStackTrace ();} P_Ja?)GT
catch(Exception e){e.printStackTrace ();} Ol^EQLO
icbYfgQ
y^fU_L?p
Utility.log(nFileLength); |I<-x)joIK
^d=@RTyo/
/ =<ul-K
return nFileLength; t|,Ex7
} %HS!^j3C%
{;~iq
Z0@ImhejuB
//保存下载信息（文件指针位置） +F6_P
private void write_nPos() QAw,XZ.K^
{ ZOsn,nF
try{ `cRB!w=KHV
output = new DataOutputStream(new FileOutputStream(tmpFile)); c3BL2>c
output.writeInt(nStartPos.length); S}I=i>QB
for(int i=0;i<nStartPos.length;i++) {iteC
{ 1Ac1CsK*
// output.writeLong(nPos); g0$k_
output.writeLong(fileSplitterFetch.nStartPos); f@g
output.writeLong(fileSplitterFetch.nEndPos); n#,l&Bx
} CplRnKra
output.close(); CR=MjmH
} %P6!vx:&^b
catch(IOException e){e.printStackTrace ();} N*-Z Jv
catch(Exception e){e.printStackTrace ();} +5\\wGo<
} ,_-*/- 7;8
d8I:F9
]jrxrUl
//读取保存的下载信息（文件指针位置） fL:Fn"Nv
private void read_nPos() BS.6d}G4
{ .`RC,R`C
try{ %05a>Rf&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _L.yt5_
int nCount = input.readInt(); v%Xe)D
nStartPos = new long[nCount]; "xI[4~'`:
nEndPos = new long[nCount]; ,6L>f.V^(U
for(int i=0;i<nStartPos.length;i++) |g!# \
{ ~(S4/d5
nStartPos = input.readLong(); "|rqt.f2[
nEndPos = input.readLong(); U]$3NIe
} 1\kehCt
input.close(); u'."E7o#
} GC3L2C0)k
catch(IOException e){e.printStackTrace ();} 8B9zo&
catch(Exception e){e.printStackTrace ();} 4Fq}*QJ-
} .9QQ]fLs
%q^]./3p
v\FD~
private void processErrorCode(int nErrorCode) SsZzYj.d
{ -/?<@*n
System.err.println("Error Code : " + nErrorCode); '_Oprx
} 5w9<_W0d
'h=2_%l@Y
RMXj)~4.
//停止文件下载 b5R*]
public void siteStop() Y6a|\K|
{ J_$~OEC~
bStop = true; bS<p dOX_
for(int i=0;i<nStartPos.length;i++) 0rUf'S ?K
fileSplitterFetch.splitterStop(); @9a=D<'>
s,x]zG"
eW%jDsC
} RdHR[Usm
} `Mg "!n`
//负责部分文件的抓取 eo[^ij
**FileSplitterFetch.java 7m:,-xp
*/ }XU- JAn
package NetFox; UJ:B:hh''
j C?
(0S7
import java.io.*; rJ>8|K[kt
import java.net.*; f6)H!SI
^Du_e(TiyK
2hP8ZfvIR
public class FileSplitterFetch extends Thread { WTx;,TNG
a6_`V;
'iK0Wr
String sURL; //File URL uip]K{/A!e
long nStartPos; //File Snippet Start Position rg\w!L(
long nEndPos; //File Snippet End Position #4>F%_
int nThreadID; //Thread's ID `0F IJT
boolean bDownOver = false; //Downing is over yM@cml6Ox
boolean bStop = false; //Stop identical mr? ii
FileAccessI fileAccessI = null; //File Access interface \mloR '
'>BHwc
0saEcJ-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v]~[~\|a
{ [qB=OxH?
this.sURL = sURL; @$]h[
this.nStartPos = nStart; QR4o j
this.nEndPos = nEnd; f`e.c_n(
nThreadID = id; >Mn.|:DF]&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R0[Gfq9M=
} oLoa71Q}
0P42C{>'w
bkTj Q
public void run() ojri~erJE?
{ lRb)Tz6SE
while(nStartPos < nEndPos && !bStop) |a+8-@-Tj
{ 26A#X
65v'/m!ys
~WSC6Bh@9
try{ |wx1 [xZ
URL url = new URL(sURL); al/~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c@`P{6
httpConnection.setRequestProperty("User-Agent","NetFox"); Wj&s5;2a
String sProperty = "bytes="+nStartPos+"-"; &n|gPp77$
httpConnection.setRequestProperty("RANGE",sProperty); *O~D lf
Utility.log(sProperty); G`jhzG
>\ W" 3.
0dW1I|jR
InputStream input = httpConnection.getInputStream(); gK /K Z8
//logResponseHead(httpConnection); 4)_ [)MZ\j
OuoZd!"qf
$)3/N&GXR
byte[] b = new byte[1024]; {+;8dtZ)x
int nRead; V.J%4&^X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZfU_4Pl->
{ @u^Ib33
nStartPos += fileAccessI.write(b,0,nRead); 43Q&<r$[T
//if(nThreadID == 1) <9"i_d%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CJ_B.
} Z5Cv$bUc
4/b#$o<I?
f[w$3
Utility.log("Thread " + nThreadID + " is over!"); y4') !e
bDownOver = true; IWkBq]Y
//nPos = fileAccessI.write (b,0,nRead); })B)-8
} ^:BRbp37i
catch(Exception e){e.printStackTrace ();} \MU4"sXw
} PA E)3
} L<:ya
dx^3(#B
yAOC<d9 E
//打印回应的头信息 o9/P/PZ\X
public void logResponseHead(HttpURLConnection con) WKG=d]5
{ 39"'Fz?1
for(int i=1;;i++) bpkn[K"(
{ wP%;9y2B
String header=con.getHeaderFieldKey(i); <:?&}'aA
if(header!=null) X*T9`]l6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &("?6%GC
Utility.log(header+" : "+con.getHeaderField(header)); rO NLbrj
else Hl#o& *Ui"
break; 3]'3{@{}H
} #xmUND`@
} *jYwcW"R{z
-&c@c@dC
{PU[MHZF
public void splitterStop() ]n{2cPx5d
{ xsfq[}eH<
bStop = true; , Le_PJY)
} -I -wdyDr
ZrTq)BZ
thh, V
} ?F-,4Ox{/
1xw},y6T2
Z1Ms~tch
/* :!%oQQO
**FileAccess.java X**wRF
*//文件访问(定位，写) R{T4AZ@,'
package NetFox; 6c2fqAF>i
import java.io.*; F?UL0Q|uv
\1tce`+
txi m|)
public class FileAccessI implements Serializable{ !54%}x)3
HjK|9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^3el-dZ
RandomAccessFile oSavedFile; O&}07(
long nPos; As"'KR
+/ #J]v-
`p!.K9r7
public FileAccessI() throws IOException 4o%hH
{ toF@@%
this("",0); pRC#DHcHh
} y"2c; *7[{
-/h$Yb
qB8<(vBP+
public FileAccessI(String sName,long nPos) throws IOException u", [ulP
{ w'UP#vT5&
oSavedFile = new RandomAccessFile(sName,"rw"); "MyYu}AD
this.nPos = nPos; U8moVj8w1
oSavedFile.seek(nPos); Fr3Q"(
} UPbG_ #"wZ
oL<^m?-u
jildiT[s
public synchronized int write(byte[] b,int nStart,int nLen) 0py0zE6,,
{ 7Q^t(
int n = -1; poM VB{U
try{ c^m}ep\F5L
oSavedFile.write(b,nStart,nLen); ]+J]}C]\d
n = nLen; wt-)5f'{
} 6n>+cX>E
catch(IOException e) f}o`3v*z
{ &Uzg&eB
e.printStackTrace (); CnJO]0Op3
} 3Y>!e#
M*%iMz
:[,n`0lH
return n; v\Q${6kEtx
} Qp{{OjD
N'TL &]
< =sO@0(<
} 1XwbsKQ}
)bqO}_B
xaejG/'iK
/* EFV'hMjS)
**SiteInfoBean.java {G_ZEo#x8,
*/ gR%fv
package NetFox; {5:y,=Y
l,L#y4#
7?e*b(vd
public class SiteInfoBean { 5_{C \S`T
qY0p)`3!%
`5Q0U%`W
private String sSiteURL; //Site's URL sAWUtJ
private String sFilePath; //Saved File's Path "Qm
private String sFileName; //Saved File's Name !fjDO!,!
private int nSplitter; //Count of Splited Downloading File .XTBy/(0
JuS#p5E #
X&pK#=
public SiteInfoBean() Z_Hc":4i
{//nSplitter的缺省值为5 le`fRq8f&
//default value of nSplitter is 5 /{^Qup
this("","","",5); wm!Y5
} l>Z"y\l=
`VwZDU~6
Z-.`JkKd8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N!{('po
{ ;i@,TU
sSiteURL= sURL; *{/BPc0*
sFilePath = sPath; <x *.M"6?
sFileName = sName; 3a_~18W
this.nSplitter = nSpiltter; *xI0hFJIM
S2'./!3yv
*shE-w;C
} l`M{Ravvn*
' cR||VX
>/9f>d?w^
public String getSSiteURL() sEm-Td+A5
{ TFjb1a,)
return sSiteURL; 1Ue)&RW
} 9(V12gn+lk
4"U/T1&
ZF!cXo7d
public void setSSiteURL(String value) w3WBgH
{ $F"'=+0
sSiteURL = value; XvETys@d
} +twl`Z3n
eg!s[1[_
?Dm={S6
public String getSFilePath() R~ n[g
{ %/iD@2r
return sFilePath; 0h=NbLr|S-
} ;+jz=9Q-
KcKdhqdN-
|qTvy,U[
public void setSFilePath(String value) |Lf>Z2E
{ 2t 7':X
sFilePath = value; a|S6r-_;s
} AUjZYp
F#Y9 @E
j.or:nF
public String getSFileName() 1seWR"
{ I8};t b#
return sFileName; R `K1L!`3
} qHVZsZ
&`x1_*l
+;,65j+n
public void setSFileName(String value) Ql>bsr}
{ `4IZ4sPi
sFileName = value; 'aV])(Wm>
} 4,EX2
"xWrYq'"
zD^*->`p
public int getNSplitter() T8^`<gr.
{ Mbm'cM&}
return nSplitter; wCQ.?*7-9Q
} 65]>6D43
(}B3df
~}"5KX\=#
public void setNSplitter(int nCount) _p*a`,tK
{ xqSoE[<v
nSplitter = nCount; ,{6Vf|?
} !(gMr1}w
} &c[ISc>N{
MD98N{+[|
h;[<4zw
/* (zr2b
**Utility.java PQj'D<G
*/ ;SgPF:T>Q
package NetFox; -kk0zg &|i
~Z`Cu~7
\X2r?
public class Utility { ctOBV
9 1.gE*D
8AVtUU
public Utility() WhT5NE9t
{ N&yr?b'!-*
{nPiIPH
A('o&H
} *qZBq&7tb
t i&!_
//线程睡眠 icK$W2<8mg
public static void sleep(int nSecond) ;#bDz}|\AN
{ eC3 ~|G_O
try{ =odKi"-6
Thread.sleep(nSecond); 7#&e0fw/I
} w2SN=X~#
catch(Exception e) &g"`J`
{ _v[gJ(F
e.printStackTrace (); cJE4uL<
} 0`/CoP<U
} []jbzVwS2
11vAx9
//日志 Te%V+l
public static void log(String sMsg) 'gtcy
{ K&VMhMVb
System.err.println(sMsg); d#HlO}
} 7,s5Gd-
Dz&,g+>$J
[<|$If99\
public static void log(int sMsg) sXmP<c
{ ||L^yI~_d
System.err.println(sMsg); )Ma/]eZ^I
} iR"6VO
} v\@pZw=x
#KNl<V+c}1
{FX]1:
/* 7p- RPC
**TestMethod.java ,D'm#Fti
*/ S,EL=3},=
package NetFox; t3AmXx
on;>iKta9
UfIr"bU6
public class TestMethod { )PkW,214#
_e/Bg~
t,n2N13
public TestMethod() XG!6[o;
{ ///xx/weblogic60b2_win.exe c39j|/!;Y
try{ l<p<\,nV$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ftKL#9,s(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !"o\H(siT
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^ir)z@P?V
fileFetch.start(); /+*N.D'`t,
} Fv*QcB9K
catch(Exception e){e.printStackTrace ();} -k@1#c+z
f5p/cUzX
]28j$)6
} /M'd$k"0z
;l1.jQh
?pcbso
public static void main(String[] args) *dxm|F98
{ c%WO#}r|
new TestMethod(); (@qPyM6~}
} ]Y-Y.&b7t
} ;aj;(Z.p)
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