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)); w0_P9g:
} d/7R}n^
for(int i=0;i<nEndPos.length-1;i++) <R7{W"QTA)
{ Zo<)r2|O.
nEndPos = nStartPos[i+1]; <a"(B*bBd
} U3{<+vSR`
nEndPos[nEndPos.length-1] = nFileLength; Z<i}XCE
} +& B?f
} .t_t)'L
5G`HJ6
hI:.Qp`r
//启动子线程 ']1n?K=A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IE`3I#v
for(int i=0;i<nStartPos.length;i++) r%.k,FzGZY
{ 0V1GX~2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TmG);B}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7%Y`j/
nStartPos,nEndPos,i); +-j-)WU?,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V'&;r'#O
fileSplitterFetch.start(); D5lQ0_IeW
} YCbvCw$Ob
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sG`x |%t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i//H5D3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \ASt&'E
nEndPos = " + nFileLength); c*)T4n[e
// fileSplitterFetch[nPos.length-1].start(); % "(&a'B
~bZ$ d{o^
G4@r_VP\
//等待子线程结束 *D?_,s
//int count = 0; "U}kp#)
//是否结束while循环 l r&7 qu
boolean breakWhile = false; qPQIcJ
lp *GJP]T
/}m)FaAi
while(!bStop) Kv| x -_7
{ 0SI@`C*1o
write_nPos(); 1B4Qj`:+0
Utility.sleep(500); PR@6=[|d
breakWhile = true; KR>)Ek
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Pf[E..HF*d
for(int i=0;i<nStartPos.length;i++) Ol>q(-ea
{ PFJ$Ia|
if(!fileSplitterFetch.bDownOver) z%D7x5!,R
{ KoERg&fY
breakWhile = false; pp@ Owpb
break; V'i-pn2gyu
} '#+&?6p
} 0vv~G\yM
if(breakWhile) }p~2lOI
break; oPKLr31zt
p3M!H2W
j9+4},>>CU
//count++; B->AY.&j
//if(count>4) fQfn7FaW_\
// siteStop(); (.4lsKN<
} Tvx1+0Z%z
d6J/)nl
v6*0@/L M
System.err.println("文件下载结束！"); aFTWzz
} Zonjk%tC
catch(Exception e){e.printStackTrace ();} ;QBS0x\f@
} : "85w#r
s)E \
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//获得文件长度 O%EA,5U.
public long getFileSize() ["3dr@T9Z
{ &&&-P\3
int nFileLength = -1; 4,)9@-|0R
try{ 1$&@wG
URL url = new URL(siteInfoBean.getSSiteURL()); L_Ok?9$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D>7a0p784
httpConnection.setRequestProperty("User-Agent","NetFox"); "/'3I/}
(7R?T}
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int responseCode=httpConnection.getResponseCode(); lb_N"90p
if(responseCode>=400) OH t)z.
{ i\sBey ND"
processErrorCode(responseCode); >bW=oTFz
return -2; //-2 represent access is error T-] {gc
} ?Lg(,-:
KwL_ae6fV
d/; tq
String sHeader; cw<IL
*z~,|DQ(A
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for(int i=1;;i++) \BnU?z
{ F rckA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); & P-8_I
//Utility.log(in.readLine()); *JJ8\R&P0
sHeader=httpConnection.getHeaderFieldKey(i); jYp!?%!
if(sHeader!=null) ?%6oM
{ 4zyQ"?A~
if(sHeader.equals("Content-Length")) 1iF=~@Nz_
{ Pe_O(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,jY:@<n
break; yT7$6x
} 'I$FOH
} %YR&>j k
else mUg :<.^
break; eh9?GUr5
} \Bo$ 3
} wK(]E%\
catch(IOException e){e.printStackTrace ();} V9) /
catch(Exception e){e.printStackTrace ();} gcA:Q4
^-"Iwy
"9caoPI0~
Utility.log(nFileLength); AT&K>NG
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@62,.\F
return nFileLength; GAj%o]}u
} Blxa0&3
od)TQSo
_LaG%* R6
//保存下载信息（文件指针位置） 3x;UAi+&
private void write_nPos() cUR :a@
{ ~(R=3
try{ 9S%5Z>
output = new DataOutputStream(new FileOutputStream(tmpFile)); So1TH%
output.writeInt(nStartPos.length); `58%&3lp
for(int i=0;i<nStartPos.length;i++) Yz/Blh%V
{ ^\ [p6>
// output.writeLong(nPos); leC!Yj
output.writeLong(fileSplitterFetch.nStartPos); R/~!km
output.writeLong(fileSplitterFetch.nEndPos); t.( `$
} vfkF@^D
output.close(); 2d.$V,U<
} *Ypn@YpSp
catch(IOException e){e.printStackTrace ();} " aG6u^%
catch(Exception e){e.printStackTrace ();} ( cs
} >?@5>wF
P*&[9)d6
'FXM7D
//读取保存的下载信息（文件指针位置） jYVs\h6
private void read_nPos() H7+"BWc
{ bWo
try{ M_E,pg=rWI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3'z$@;Ev+
int nCount = input.readInt(); 7ui<2(W@0
nStartPos = new long[nCount]; 7fR5V
nEndPos = new long[nCount]; HA0!>_I dC
for(int i=0;i<nStartPos.length;i++) :Qge1/
{ FOG{dio
nStartPos = input.readLong(); x$d[Ovw-
nEndPos = input.readLong(); h?xgOb!4
} p7|I>8ur.
input.close(); d'';0[W)
} X~r9yl>
catch(IOException e){e.printStackTrace ();} LACrg
catch(Exception e){e.printStackTrace ();} o ]*yI[\
} x {NBhq(4
GJ%^hr`P
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private void processErrorCode(int nErrorCode) B=cA$620
{ Ic0Sb7c
System.err.println("Error Code : " + nErrorCode); /GgID!8
} <O+GXJ2
a}@b2Wc*
|?88EG@05
//停止文件下载 Ge2Klyi
public void siteStop() 0S5xmEzop
{ 1?.CXqK
bStop = true; O<$w-(
for(int i=0;i<nStartPos.length;i++) d ~M;
fileSplitterFetch.splitterStop(); 0T`Qoo>u
E>_Rsw *
4~}NB%,
} 4V:W 8k 9D
} x:)H Ii q/
//负责部分文件的抓取 +^BThrB
**FileSplitterFetch.java 1J!v;Y\\
*/ LLgw1 @-D
package NetFox; No7-fX1B
;{I9S'
@}q, ';H7
import java.io.*; li%@HdA!
import java.net.*; 0cmd +`
/l7 %x.
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public class FileSplitterFetch extends Thread { OL\-SQ&
A-r;5?S
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String sURL; //File URL i431mpMa
long nStartPos; //File Snippet Start Position T:Cq}4k<
long nEndPos; //File Snippet End Position &oG>Rqkm
int nThreadID; //Thread's ID G u`xJ
boolean bDownOver = false; //Downing is over WHC/'kvF
boolean bStop = false; //Stop identical r-T1^u
FileAccessI fileAccessI = null; //File Access interface `<tRfl}qs
fn<dr(Dx
VrW]|jIu*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]|3hK/
{ bhUE!h<
this.sURL = sURL; &n1Vv_Lb
this.nStartPos = nStart; [k 7HLn)
this.nEndPos = nEnd; 8U@f/P
nThreadID = id; o`CM15d*7o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RFbf2s\t
} ;}Jv4Z
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public void run() qXtC7uNj$
{ cpk\;1&t
while(nStartPos < nEndPos && !bStop) !mK()#6
{ Sd6O?&(
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%i?
try{ Py*WHHO
URL url = new URL(sURL); bg|$1ue
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j*QdD\)
httpConnection.setRequestProperty("User-Agent","NetFox"); S5JMt;O
String sProperty = "bytes="+nStartPos+"-"; )L&y@dy)
httpConnection.setRequestProperty("RANGE",sProperty); w yxPvI`
Utility.log(sProperty); q&:7R .Ci
fExFpR,`
7NJl+*u
InputStream input = httpConnection.getInputStream(); d>Tv?'o`q
//logResponseHead(httpConnection); <7y/)b@
o+x%q<e;c
pS8\B
byte[] b = new byte[1024]; E#P#{_BR^
int nRead; w#1BHx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 46vC/
{ ">7xSWR*4
nStartPos += fileAccessI.write(b,0,nRead); p@78Xmu?q
//if(nThreadID == 1) UG.:D';3,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v^eAQoFLhN
} >C,0}lj
rZ,qHM
MZ%J ]Nd
Utility.log("Thread " + nThreadID + " is over!"); ds*gL ~k^
bDownOver = true; 1R_@C.I
//nPos = fileAccessI.write (b,0,nRead); 2l,>x
} P:g!~&Q
catch(Exception e){e.printStackTrace ();} e_!h>=$%8
} Jm ,:6T
} FTUfJIVN(
t!wbT79/
pOK=o$1V8
//打印回应的头信息 ;ZB=@@l(
public void logResponseHead(HttpURLConnection con) 1o5kP,)
{ 0VvY(j:hp
for(int i=1;;i++) ~d&&\EZ
{ &DGqY5=
String header=con.getHeaderFieldKey(i); G!`%.tH
if(header!=null) zji9\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eLT3b6'"?
Utility.log(header+" : "+con.getHeaderField(header)); ~V(>L=\V;
else 8/2Wq~&
break; UK OhsE
} F$>#P7ph\a
} >c@! EPS
t[k ['<G
h<3bv&oI .
public void splitterStop() Rm3W&hQ
{ [e,xC!2
bStop = true; \u.5_ g
} >? o5AdZ
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} &H+wzx<
o?O ZsA
lLVD`)
/* R)d_0Ng
**FileAccess.java 3B[tbU(
*//文件访问(定位，写) dDiy_Q6
package NetFox; &pl)E$Y
import java.io.*; <.g)?nj1
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0F uj-q
public class FileAccessI implements Serializable{ W\Il@Je;
9Cd=^Im5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B_#M)d O
RandomAccessFile oSavedFile; E>@]"O)=M,
long nPos; tM@%EO
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public FileAccessI() throws IOException "/O07l1Q<
{ {uwPP2YD,
this("",0); =Q;dYx%I5
} \B 8j9
&: LE]w
/W>?p@j+K
public FileAccessI(String sName,long nPos) throws IOException aIT0t0.
{ q8_E_s-U,
oSavedFile = new RandomAccessFile(sName,"rw"); p8]XNe
this.nPos = nPos; W;Dik%^tg
oSavedFile.seek(nPos); z__{6"^
} O 8l`1
Y)8 Py1}
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public synchronized int write(byte[] b,int nStart,int nLen) b7'A5]X
{ cooicKS7
int n = -1; *W=1yPP
try{ Qt"jU+Zoy
oSavedFile.write(b,nStart,nLen); ko!]vHB9`
n = nLen; r 'ioH"=
} 1=_?Wg:
catch(IOException e) 4J9Y
{ >]Mhkf/=)
e.printStackTrace (); 9R+ qw
} ,o2x,I
JWM4S4yZHR
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return n; iMYJVB=
} 0kp{`3ce
" u]X/ {L
3DjX0Dx/l
} f#38QP-T
<@>icDFEHn
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/* YqKQm+G
**SiteInfoBean.java mst;q@
*/ Ux);~P`/o
package NetFox; ZjK'gu8*
@gx]3t*]I
YFcMU5_F
public class SiteInfoBean { ]7,0}q.
!':y8(Ou
Q >h7H{c
private String sSiteURL; //Site's URL 0 4ceDe
private String sFilePath; //Saved File's Path !9S!zRy@
private String sFileName; //Saved File's Name R-Tf9?)
private int nSplitter; //Count of Splited Downloading File ,[|i^
sEb*GF*.V
lR ZuXo9<
public SiteInfoBean() /jc; 2
{//nSplitter的缺省值为5 ){J,Z*&
//default value of nSplitter is 5 uq!d8{IMu
this("","","",5); Re;[S[D7
} (^|vN;
0;5qo~1
utdus:B#0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -!j5j:RR
{ ,PWMl[X
sSiteURL= sURL; 0VgsV;
sFilePath = sPath; *%]&5
sFileName = sName; |'k7 ;UW
this.nSplitter = nSpiltter; jjoyMg95
=,U~
Cj)*JZVG
} -C*UB
.A6Jj4`-
|3EKK:RE
public String getSSiteURL() uw&p)
{ gr>>]C$
return sSiteURL; C%P"\>5@
} )k6z
r[nvgzv@
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public void setSSiteURL(String value) GZiN&}5e
{ d?GB#N|+g
sSiteURL = value; I(Q3YDdb
} ]EvK.ORy
F$,i_7Z&6
ibuoq X`
public String getSFilePath() |HTTTz9R.
{ O=}jg0k
return sFilePath; C/z0/mk
} KupQtT<
{@67'jL
PAjH*5IA
public void setSFilePath(String value) @3Mp>u/
{ 3AC/;WB9
sFilePath = value; uWrvkLGN
} Qvhy9Cr;
nxx&aq(._
N9AM% H$7
public String getSFileName() :W}M$5|
{ 4q`e<!MP)q
return sFileName; ,6T3:qkkvF
} 8|S}!P"
X_J(P?
$-BM`Zt0;
public void setSFileName(String value) }FAO.
{ ,a@jg&Mb]
sFileName = value; T oK'Pd
} +Ft@S(IE
oAq<ag\qV
=8 Jq'-da
public int getNSplitter() /HM0p
{ /-C6I:
return nSplitter; uU`Mq8)R
} FP h1}qS
wb (quu
k9oLJ<.k
public void setNSplitter(int nCount) e_t""h4D
{ p>0n~e
nSplitter = nCount; y(Ck j"
} `Ct fe8
} ood,k{
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L=-v>YL+
/* KFn[
**Utility.java drf?7%v
*/ Z/[ww8b.
package NetFox; ~g|z7o
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public class Utility { HF]|>1WV[
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public Utility() 4A~1Z,"%v(
{ DH{^9HK
ycSC'R
g/e2t=qP
} ]='zY3
D eM/B5qw
//线程睡眠 %Ig3udcY?
public static void sleep(int nSecond) IO]%AL(.;
{ +OX:T) 4h6
try{ z!:%Hbh=
Thread.sleep(nSecond); L{AfrgN
} _';oT*#
catch(Exception e) ,e5#wz
{ !p|d[
e.printStackTrace (); md`"zV
} YgW 50)q^
} wYLJEuS|
gOKF%Ej31T
//日志 s^Rig[
public static void log(String sMsg) +*ZF52hy|
{ 6-h(305A
System.err.println(sMsg); +{pS2I}d
} A1V^Gi@i
{S5HH"
`KUl XS(
public static void log(int sMsg) 1|/]bffg!c
{ iF'qaqHWY4
System.err.println(sMsg); !1cVg ls|
} "kg;fF|
} Tg|/UUn
a\?-uJ+
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/* zKX|m-i|2
**TestMethod.java !;s5\91
*/ t*{BN>B
package NetFox; r*XEne
i*ErxWzu
/r@~"Rx'
public class TestMethod { h;?H4j
1/%g VB8
`c%{M4bF\
public TestMethod() x|`o7.
{ ///xx/weblogic60b2_win.exe xN=:*#Z"pb
try{ [$AOu0J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m6^n8%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <maYS2
SiteFileFetch fileFetch = new SiteFileFetch(bean); @fO[{V
fileFetch.start(); ?kKr/f4N
} U>=& 2Z2?
catch(Exception e){e.printStackTrace ();} Q/<?v!h{
XpU%09K
q7ubRak
} oVYW'~OID
, UiA?7k
#Z>EX?VS:
public static void main(String[] args) u[G`_Y{=EM
{ B #zU'G*Y
new TestMethod(); MiB}10
} l0-zu6iw
} mel(C1b"j/
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