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)); [")0{LSA=
} =pk'a_P8-
for(int i=0;i<nEndPos.length-1;i++) CC)9Ks\
{ y.O? c&!
nEndPos = nStartPos[i+1]; A%GJ|h,i
} IcQ?^9%{
nEndPos[nEndPos.length-1] = nFileLength; Z(<ul<?r
} piId5Gx7
} Q1jyetk~I
s]I],>}RU
F;b|A`M
//启动子线程 mdZELRu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 78.sf{I
for(int i=0;i<nStartPos.length;i++) <5X@r#Lz
{ ;8T<L[ ^U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .1pEq~>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zu^ AkMc
nStartPos,nEndPos,i); $<aBawLZO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "|Pl(HX
fileSplitterFetch.start(); /C(L(X
} xJ"KR:CD>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {[s<\<~B*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cYp}$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N!m%~},s//
nEndPos = " + nFileLength); V`H#|8\i
// fileSplitterFetch[nPos.length-1].start(); {$EXI]f
@"~\[z5
G` 8j ^H,
//等待子线程结束 r]E$uq bR
//int count = 0; !e7vc[N
//是否结束while循环 )a}5\V
boolean breakWhile = false; )R|7> 97
[-CG&l2?L
-0]aOT--
while(!bStop) NRl"!FSD;"
{ o}%fs *
write_nPos(); r zvX~B6
Utility.sleep(500); 2Z97Tq
breakWhile = true; $?s^HKF~
s{IoL_PJP
_4W#6!
for(int i=0;i<nStartPos.length;i++) srSTQ\l4
{ x:bYd\ EJ[
if(!fileSplitterFetch.bDownOver) <VBw1|)$@
{ :1{j&$
breakWhile = false; "/"qg
break; |`okIqp
} 4ku/3/6
} {Q-U=me\
if(breakWhile) %*gO<U4L]
break; roA1=G\Q
+sI.GWQ_:
a(7ryl~c=
//count++; xC{NIOYn'
//if(count>4) ~3%3{aa
// siteStop(); U\ L"\N7
} xL BG}C
j*zK"n
M'HOw)U
System.err.println("文件下载结束！"); j"V$J8)[
} 35>}$1?-6
catch(Exception e){e.printStackTrace ();} |. 6@-h~8
} f@{C3E dd
IF:M_
6Te}"t>
//获得文件长度 p3S c4
public long getFileSize() kmoJ`W} N
{ Z])_E6.
int nFileLength = -1; n,F00YR
try{ % n{W
URL url = new URL(siteInfoBean.getSSiteURL()); ${+.1"/[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zfZDtKq
httpConnection.setRequestProperty("User-Agent","NetFox"); m=9N^_
VMWg:=~$
}"-r;i
int responseCode=httpConnection.getResponseCode(); !BX62j\?
if(responseCode>=400) f+920/>!Z
{ R\}YD*
processErrorCode(responseCode); M BT-L
return -2; //-2 represent access is error ^55?VQB
} |FFC8R%@]u
HFr3(gNj@
Wy4^mOv
String sHeader; >S!DIL
OGFKc#
!.9vW&t
for(int i=1;;i++) [FL I+;gY
{ , .I^ekF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2UF94
//Utility.log(in.readLine()); =#tQIhX`
sHeader=httpConnection.getHeaderFieldKey(i); DSC4
if(sHeader!=null) b8>9mKs
{ ddP,_.0
if(sHeader.equals("Content-Length")) @QG1\W'
{ `k&K"jA7$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l:eNu}{&
break; C6w{"[Wv=X
} f 99PwE(=
} <<6w9wNon
else G!8pF
break; ?nW#qy!R
} As|/ O7%
} sQZ8<DpB
catch(IOException e){e.printStackTrace ();} f>dkT'4
catch(Exception e){e.printStackTrace ();} ,7P^]V1
!P$xh
\2pFFVT
Utility.log(nFileLength); A232"p_
E5 oD|'=WA
k_>{"Rc
return nFileLength; MuGg z>CV[
} 3.X0!M;x
qJU)d
YSo7~^1W"
//保存下载信息（文件指针位置） #&83;uys
private void write_nPos() .,Qnn}:l
{ F5+_p@!i
try{ gi'agB^
output = new DataOutputStream(new FileOutputStream(tmpFile)); A#S:_d
output.writeInt(nStartPos.length); <UJJ],)^1A
for(int i=0;i<nStartPos.length;i++) 7[BL 1HI*
{ |nN/x<v
// output.writeLong(nPos); io7U[#
output.writeLong(fileSplitterFetch.nStartPos); C-u/{CP
output.writeLong(fileSplitterFetch.nEndPos); ATM:As:<@
} ^~qs-.?
output.close(); %uVJLz
} -5 /v`
catch(IOException e){e.printStackTrace ();} ~[TKVjyO
catch(Exception e){e.printStackTrace ();} *"FLkC4
} 2?iOB6
_M[[vXH
zL'IN)7MU
//读取保存的下载信息（文件指针位置） %D(prA_w
private void read_nPos() ;&6PL]/d
{ ;-pvc<_c<
try{ 1lyOp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @O}j:b
int nCount = input.readInt(); +esNwz_
nStartPos = new long[nCount]; 6^O?p2xpo
nEndPos = new long[nCount]; Ln2C#Uf
for(int i=0;i<nStartPos.length;i++) t* vg]Yc
{ %K'*P56
nStartPos = input.readLong(); _SC
nEndPos = input.readLong(); ?vn 0%e868
} 1{x~iZa
input.close(); ZT"|o\G^Q
} 7. 9s.*
catch(IOException e){e.printStackTrace ();} 6'Yn|A
catch(Exception e){e.printStackTrace ();} b+].Uc
} Mp"ci+Iu
@gSFvb bc
2~WFLD
private void processErrorCode(int nErrorCode) Pgw%SMEp
{ LQ\ ELJj
System.err.println("Error Code : " + nErrorCode); VnSj:LUD
} B9IXa;
* \o$-6<
N~; khS]
//停止文件下载 )^f9[5ee
public void siteStop() {L4>2rF
{ t9n
bStop = true; ]9&q'7*L
for(int i=0;i<nStartPos.length;i++) YD46Z~$
fileSplitterFetch.splitterStop(); _8b]o~[Z+
?ey&Un"
MAe<.DHY
} b^,Mw8KsO
} _SIs19"lR
//负责部分文件的抓取 fE%[j?[
**FileSplitterFetch.java 0uIV6LI
*/ R g0 XW6
package NetFox; 4nII/cPG
z[\W\g*|ri
YNC0Z'c9
import java.io.*; qN1 -plY
import java.net.*; #EmffVtY
j&[.2PW\
O/Mz?$8J
public class FileSplitterFetch extends Thread { J4[x,(iq(
x1:Pj
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String sURL; //File URL _Hd1sx
long nStartPos; //File Snippet Start Position <a+eF}*2
long nEndPos; //File Snippet End Position $}^\=p}X
int nThreadID; //Thread's ID I*W9VhIOV
boolean bDownOver = false; //Downing is over @ojg`!,
boolean bStop = false; //Stop identical h76NR
FileAccessI fileAccessI = null; //File Access interface \'??
YR|(;B
}^pQbFku
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zh^jWu
{ #'4<> G]
this.sURL = sURL; WE5"A| =
this.nStartPos = nStart; k?["F%)I
this.nEndPos = nEnd; fmnRUN=
nThreadID = id; LZQFj/,Jg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 20/P M9
} i|c`M/) h:
:!I)r$
/m Q2;*|
public void run() mI7rx`4H
{ =nvAOvP{?
while(nStartPos < nEndPos && !bStop) b#p~F}qT
{ rKzv8d
ayH% qp
//X e*0
try{ E+m]aYu"
URL url = new URL(sURL); ?)?IZ Qj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V#zhGAMy.
httpConnection.setRequestProperty("User-Agent","NetFox"); Nxbd~^j
String sProperty = "bytes="+nStartPos+"-"; nb0 Py>4
httpConnection.setRequestProperty("RANGE",sProperty); ?GUz?'d
Utility.log(sProperty); Ez/\bE
r*i$+ Z
kMl@v`
InputStream input = httpConnection.getInputStream(); z;bH<cQ
//logResponseHead(httpConnection); B:3+',i1
l&6U|q`
vbRrk($`
byte[] b = new byte[1024]; /$FXg;h9$
int nRead; 4-]Do?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -7-Fd_F8
{ *xX(!t'
nStartPos += fileAccessI.write(b,0,nRead); [+;FV!M6
//if(nThreadID == 1) [GR]!\!%~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bmj8WZ
} aCU7w5
\3H<z@;
;Cr_NP[8|j
Utility.log("Thread " + nThreadID + " is over!"); cg(QjH"
bDownOver = true; ( }]37
//nPos = fileAccessI.write (b,0,nRead); W{fULl
} +A8=R%&b)[
catch(Exception e){e.printStackTrace ();} Kk!6B
} >a&?AP #
} ]]p19[4s
5,HCeN
l zfD)TWb
//打印回应的头信息 ' "ZRD_"
public void logResponseHead(HttpURLConnection con) {BFT
{ F5N>Uqr*oN
for(int i=1;;i++) [{S;%Jj*X/
{ ?%cn'=>ZI
String header=con.getHeaderFieldKey(i); Sni&?tcY
if(header!=null) jIAW-hc]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,}9f(`
Utility.log(header+" : "+con.getHeaderField(header)); js:C mnI
else do:QH.q8)
break; tA`mD>[
} *.kj]BoO
} P]pmt1a
O" %Hprx
E$]a?uA:
public void splitterStop() KI Ek/]<H
{ gCv"9j<j
bStop = true; Dk)@>l:gI,
} 8ivRp<9
:D"@6PC]
)^t!|*1LA
} Ms.PO{wb
P['X<Xt8
IXGW2z;
/* [ 3$.*
**FileAccess.java =E;=+eqt
*//文件访问(定位，写) \e?.hmq
package NetFox; 2Ryp@c&r^
import java.io.*; uew0R;+oa
/a@ kS
e{,!|LhpQ
public class FileAccessI implements Serializable{ \Os:6U=X-
s{yJ:WncI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :&Qb>PH[
RandomAccessFile oSavedFile; 'n~fR]h}
long nPos; sS C?io
60`+9(^
fph-v-cl
public FileAccessI() throws IOException n`P`yb\f$
{ ?ouV
this("",0); &(gm4bTg
} i4hJE
n4^*h4J7
/wr6\53J
public FileAccessI(String sName,long nPos) throws IOException QZ?d2PC=>?
{ S*4f%!
oSavedFile = new RandomAccessFile(sName,"rw"); <e'P%tG'
this.nPos = nPos; Af`z/:0<
oSavedFile.seek(nPos); W&<g} N+
} h]qT1(I
F vj{@B!
+Qt[1Xq
public synchronized int write(byte[] b,int nStart,int nLen) ]x1p!TSU
{ ^rL,&rk
int n = -1; <#>Oy&E
try{ "cwR^DoD&
oSavedFile.write(b,nStart,nLen); G]b8]3^
n = nLen; ?~!tM}X0:3
} u0xQ;BQ
catch(IOException e) *]5z^> q;7
{ ]K7`-p~T
e.printStackTrace (); x7f:F.
} !;i*\ a
5!~!j "q
S0F@#mSQ?
return n; fVYiwE=F
} +Z ><
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P2Onkl
} kg:l:C)Tq
Te+^J8
H-185]7
/* 0Su_#".-*
**SiteInfoBean.java oB4#J*
*/ 2sUbiDe-
package NetFox; TaOOq}8c#
)Lb72;!?
8\DME
public class SiteInfoBean { w$b~x4y%
0F^]A"kF
aRX
private String sSiteURL; //Site's URL 3x![8 x
private String sFilePath; //Saved File's Path e[}],W
private String sFileName; //Saved File's Name xo(k?+P>.
private int nSplitter; //Count of Splited Downloading File A';n6ne%i
' X}7]y
@LcT-3u
public SiteInfoBean() qp\BV#E
{//nSplitter的缺省值为5 [yC"el6PM
//default value of nSplitter is 5 /tP7uVL R
this("","","",5); qtzFg#
} qL3@PSN?|
r sLc&2F
E`tQe5K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p'80d:
{ E3f9<hm
sSiteURL= sURL; AVv#\JrRW
sFilePath = sPath; TMww
sFileName = sName; { UOhVJy
this.nSplitter = nSpiltter; WO@H*
8[~~gYl
{S*!B
} 6Hwxx5>r
D M}s0O$0
0Z,{s158L
public String getSSiteURL() 7G"7wYc>R
{ .EG*+,
return sSiteURL; =53bLzr
} )tD6=Iz^5
"XhOsMJ
*> KHRR<N
public void setSSiteURL(String value) 5qRc4d'
{ r4?b0&Xq
sSiteURL = value; 5>P7]?U.]
} wyzOcx>M
|!Fk2Je,
&n|*uLn
public String getSFilePath() -;>#3O-
{ [f/.!@sj
return sFilePath; um[!|g/
} rrcwtLNbu
{i>Jfl]G}
$/paEn"
public void setSFilePath(String value) _88QgThb
{ U` hfvTi
sFilePath = value; 8R}K?+]
} @!<d0_dnC
f05=Mc&)
x'qWM/
public String getSFileName() -`Q}tg>cT
{ Vho0eV=
return sFileName; 30_ckMG"g
} |sf*hlrJ
~{M@?8wi
%b=p< h'(
public void setSFileName(String value) 8*s7m
{ %iJ|H(P
sFileName = value; P"F{=\V1`<
} q}wj}t#
c 0-w6
)o jDRJ&
public int getNSplitter() hwVAXsF~
{ h!e2 +4{4{
return nSplitter; J &{xP8uq_
} Obo_YE
eh<rRx"[
]*;F. pZ
public void setNSplitter(int nCount) Go <'
{ 7F(5)Utt
nSplitter = nCount; 6Y7H|>g)
} <GF@L
} #6W,6(#^#
sx5r(0Z
SY1GR n
/* n+;vjVS%
**Utility.java 2+'|kt2
*/ ,J(lJ,c
package NetFox; hD q2-X}
-eml
.X'< D*
public class Utility { }fA;7GW+9
?z=\Ye5x
U=cWmH
public Utility() QU/3X 1W
{ tg85:
NfwYDY
\H4U8)l
} Y)M8zi>b
T'1gy}
//线程睡眠 `FJ|W6%
public static void sleep(int nSecond) {Q~7M$
{ Hm9<fQuM
try{ A-wRah.M
Thread.sleep(nSecond); [w+Q^\%bN
} hNbIpi=
catch(Exception e) PAZ$_eSK6
{ V=}1[^
e.printStackTrace (); kdcQw7G
} <o0~H
} )acV-+{
\c7>:DH
//日志 tln1eN((q
public static void log(String sMsg) 6OB",
{ M"U OgS
System.err.println(sMsg); vM4<d>
} 64U6C*w+
>85zQ 1aL
#?&0D>E?k
public static void log(int sMsg) HY)ESU !
{ mqFq_UX/T
System.err.println(sMsg); ;&f1vi4
} ^od<JD4
} K]fpGo
Hk;-5A|9
zn)yFnB!TH
/* `;F2n2@
**TestMethod.java Fr5 Xp
*/ 3z[$4L'.
package NetFox; @`|)Ia<
Q2s&L]L=
ctI{^f:
public class TestMethod { @-"R$HOT
9y~"|t
w%xCTeK[
public TestMethod() s-?fUqA
{ ///xx/weblogic60b2_win.exe m22wF>9
try{ kMxjS^fr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'M/([|@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K+),?Q ?.p
SiteFileFetch fileFetch = new SiteFileFetch(bean); lf$Ve
fileFetch.start(); fKkjn4&W
} 9lspo~M
catch(Exception e){e.printStackTrace ();} Ty+I8e]{
)`?%]D
V3.t;.@
} zxKCVRJ
%}b8aG+
LM.`cb;?G
public static void main(String[] args) QxpKX_@Q5
{ YYUe)j{T
new TestMethod(); #Ufo)\x
} 213\ehhG<
} >Ko[Xb-8^_
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