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)); o0ZIsrr
} ?aBj#
for(int i=0;i<nEndPos.length-1;i++) ak;6z]f8[
{ n@!wp/J,
nEndPos = nStartPos[i+1]; +\0T\;-Xe
} Vtb1[cnna
nEndPos[nEndPos.length-1] = nFileLength; n`(~OO
} {Oj7
} |uI?ySF
jin db#)bz
#;[Bl=3(
//启动子线程 @%1IkvJV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G?`-]FMO
for(int i=0;i<nStartPos.length;i++) ;+ azeW^
{ 0VN7/=n|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zB*euHIqZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L@RIZu>ZW+
nStartPos,nEndPos,i); hN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -v]Qhf&>
fileSplitterFetch.start(); )%mg(O8uL
} s)zJT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }`xdWY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _;hf<|c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OfTfNhpK
nEndPos = " + nFileLength); 5RF4]$zT
// fileSplitterFetch[nPos.length-1].start(); 0,_b)
ESTM$k}X
gZO&r#
//等待子线程结束 VO=!8Yx[
//int count = 0; A`[@8
//是否结束while循环 7(bQ}mHl\
boolean breakWhile = false; j8++R&1f]
f'X9HU{Cz
.oqIZ\iik
while(!bStop) hmpr%(c`
{ wpXgPVZT
write_nPos(); ,:)`+v<
Utility.sleep(500); 1!1!PA9u
breakWhile = true; {EA1vo"
1@>$ Gcc
|mhKIis U
for(int i=0;i<nStartPos.length;i++) eQUe >*
{ d(-EcY>?
if(!fileSplitterFetch.bDownOver) \OQkZ.cU;
{ R_ ZK0ar
breakWhile = false; $TG=w
break; c6&Q^p|CF
} "?3`
} !E2W\chi
if(breakWhile) %Jp|z? [/
break; 8|@9{
e(?]SU|
=2Cj,[$
//count++; wM~H(=s`D
//if(count>4) wi_'iv
// siteStop(); 7b[wu~'( n
} 5'KA'>@
),(V6@Z?
/(hUfYm0
System.err.println("文件下载结束！"); Kcy@$uF{2
} [;A[.&6
catch(Exception e){e.printStackTrace ();} IgIYguQ
} /mA,F;
PLX>-7@
=-"c*^$]
//获得文件长度 nhT-Ido
public long getFileSize() v+G=E2Lhv
{ y7/F_{
int nFileLength = -1; j$Ab>}g]
try{ L\%orLEmK
URL url = new URL(siteInfoBean.getSSiteURL()); 0.TaXbi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v6GPS1:a
httpConnection.setRequestProperty("User-Agent","NetFox"); i#/]KsSp
W3H+.E
HCWNo
int responseCode=httpConnection.getResponseCode(); +s++7<C
if(responseCode>=400) S >yLqPp
{ [sF(#Y:I
processErrorCode(responseCode); H[ m<RaG8
return -2; //-2 represent access is error M|,mr~rRG
} `=UWqb(K_
@-HG`c ct
]bZ(HC?KZr
String sHeader; rHjq1-t
l12{fpm
rV6/Tdy
for(int i=1;;i++) x3 >
{ /w(e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |~!U4D\
//Utility.log(in.readLine()); t]aea*B
sHeader=httpConnection.getHeaderFieldKey(i); -=`#fDvBn
if(sHeader!=null) 0@I S
{ "ZwKk G
if(sHeader.equals("Content-Length")) ,<-G<${
{ #|[ M?3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6eFp8bANN#
break; ^r6!l.
} [F!Y%Zp
} w[tmCn+
else U8.7>ENnP&
break; _>+8og/%@
} R:X0'zeRr
} T*g:# ^4
catch(IOException e){e.printStackTrace ();} i|`dWOVb
catch(Exception e){e.printStackTrace ();} ]:>,A@7
aJ Z"D8C
Gg Jf7ie4
Utility.log(nFileLength); -m *Sq
Lk\P7w{
u .f= te
return nFileLength; 21hv%CF\9
} zk-.u}RBFG
kF(n!2"W
7lV.[&aKW
//保存下载信息（文件指针位置） i4Lc$20?d
private void write_nPos() #7ohQrP
{ [e[<p\]
try{ I9h ?;(
output = new DataOutputStream(new FileOutputStream(tmpFile)); H0m|1 7
output.writeInt(nStartPos.length); LUB${0BrA
for(int i=0;i<nStartPos.length;i++) y!tC20Q
{ KlRr8G!Z
// output.writeLong(nPos); h/?l4iR*
output.writeLong(fileSplitterFetch.nStartPos); ;X*cCb`h
output.writeLong(fileSplitterFetch.nEndPos); )e5 @
} wLK07e(
output.close(); *na?n2Yzt
} A,sr[Pa@
catch(IOException e){e.printStackTrace ();} '5&s=M_
catch(Exception e){e.printStackTrace ();} .<@8gNm3
} [ ol9|sdu
kuyjnSo9i
hxQqa 0B
//读取保存的下载信息（文件指针位置） y@0E[/O
private void read_nPos() ]vwW]O7
{ Pj}66.
try{ VD_$$Gn*q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Zm6{n'
int nCount = input.readInt(); zR2B- &]H
nStartPos = new long[nCount]; `tP7ncky
nEndPos = new long[nCount]; _S>JKz
for(int i=0;i<nStartPos.length;i++) lXcx@#~
{ [w% qV 6
nStartPos = input.readLong(); |{CfWSB7~@
nEndPos = input.readLong(); 8Z(Mvq]f&
} *98$dQR$
input.close(); 6I@h9uIsze
} "[y-+)WTG
catch(IOException e){e.printStackTrace ();} g+J-Zg6
catch(Exception e){e.printStackTrace ();} (sh)TBb5
} ?@E!u|]K
}Y;K~J
gNt(,_]ZR
private void processErrorCode(int nErrorCode) z`:lcF{V
{ (Jz1vEEV
System.err.println("Error Code : " + nErrorCode); |JQQU!x
} 293M\5:
H1} RWaJ
#O+),,WS
//停止文件下载 Q%xC}||1s"
public void siteStop() C=eF.FB;'
{ h*-Pr8
bStop = true; z CvKDlL
for(int i=0;i<nStartPos.length;i++) zux{S;:?
fileSplitterFetch.splitterStop(); iyg*Xbmi~.
%}%Qc6.H
Z]B~{!W1
} @nux9MX<9
} ]*AR,0N&
//负责部分文件的抓取 {WYX~Mvvj
**FileSplitterFetch.java ZpnxecJUJ
*/ Za1QC;7
package NetFox; %44leINx
UEguF&
e J6$-r
import java.io.*; =>_\fNy
import java.net.*; 'IwNTM
<ZNzVnVA
RS8Hf~0G
public class FileSplitterFetch extends Thread { \SBc;
>k (C
b45-:mi!&#
String sURL; //File URL ~{jcH
long nStartPos; //File Snippet Start Position "hsb8-
long nEndPos; //File Snippet End Position <i&_ooX
int nThreadID; //Thread's ID ~vyf4TF<#
boolean bDownOver = false; //Downing is over sVOyT*GY
boolean bStop = false; //Stop identical |aVn&qK
FileAccessI fileAccessI = null; //File Access interface t+!$[K0/
hpD!2 K3>
'h,VR=e<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `Tv[DIVW
{ "$YJX1u3
this.sURL = sURL; |>dI/_'
this.nStartPos = nStart; =w{Z@S(ukz
this.nEndPos = nEnd; vkri+:S3
nThreadID = id; lE4HM$p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _sTROd)Vh
} =`H@%
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OG>}M$Ora
public void run() ,,q10iF
{ toBHkiuD
while(nStartPos < nEndPos && !bStop) 4bYK}oS
{ 8ap%?
z?R|Ok
!WQ-=0cm
try{ oYm[V<nIl
URL url = new URL(sURL); nH[yJGZYSA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wa{`VS
httpConnection.setRequestProperty("User-Agent","NetFox"); @eKec1<
String sProperty = "bytes="+nStartPos+"-"; )QU
httpConnection.setRequestProperty("RANGE",sProperty); ! t?iXZ
Utility.log(sProperty); :%,:"
Ezd_`_@R
J;8IY=
InputStream input = httpConnection.getInputStream(); wNpTM8rfU#
//logResponseHead(httpConnection); Y,^@P
CDK5
!xo{-@@wS
byte[] b = new byte[1024]; CTq&-l:f
int nRead; Nh_Mz;ITuu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B#Vz#y
{ r{L> F]Tw
nStartPos += fileAccessI.write(b,0,nRead); >I-RGW'A
//if(nThreadID == 1) *Doa*wQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jtW!"TOY
} S.-TOE
'!!CeDy
! |<Fo'U
Utility.log("Thread " + nThreadID + " is over!"); kuszb~`zPY
bDownOver = true; BBwy,\o#
//nPos = fileAccessI.write (b,0,nRead); \Je0CD=e`
} 3q\,$*D.
catch(Exception e){e.printStackTrace ();} KBx6NU?;PO
} ^:^9l1]
} eg;~zv
Z`ID+
5B3G @KR
//打印回应的头信息 \fz<.l]
public void logResponseHead(HttpURLConnection con) A$Hfr8w1u
{ R{<kW9!
for(int i=1;;i++) Q ayPo]O
{ jaII r06
String header=con.getHeaderFieldKey(i); v3~?;f,l
if(header!=null) }ppN k:B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <Tzrj1"Q3
Utility.log(header+" : "+con.getHeaderField(header)); D9^h; 8
else n|Q@UPb/=
break; *x@Onj
} .WA-&b_
} CQF:Rnb
8lvV4yb
g+vva"
public void splitterStop() RO+GK`J
{ Lo{ E:5q
bStop = true; G|!Tj X7s
} vlmB`T
qouhuH_WtJ
%Nlt H/I
} M?Y;a5{
n'n/Tu
;K:zmH
/* bzBEX mC
**FileAccess.java x<tb
*//文件访问(定位，写) i[7\[
package NetFox; ^}/PGG\~r
import java.io.*; le|~BG hL
<\rT%f}3^
o=1Uh,S3R
public class FileAccessI implements Serializable{ B+P(M!m3
4gI/!,J(b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jS]ru-5.
RandomAccessFile oSavedFile; +%yfcyZ.
long nPos; x kx^%3dV
ey7 f9
+h|`/ &,
public FileAccessI() throws IOException %(3|R@G.
{ +"\sc;6m.
this("",0); P+@/O
} t<.)Z-Ii
n{n52][J]
dk[!V1x4\
public FileAccessI(String sName,long nPos) throws IOException yj 3cyLXw
{ CGW.I$u
oSavedFile = new RandomAccessFile(sName,"rw"); T*Y~\~Jhu
this.nPos = nPos; [kVS O
oSavedFile.seek(nPos); a!6{:8Zi0
} >)fi^
q/4J.jL
9UdM`v)(
public synchronized int write(byte[] b,int nStart,int nLen) rK'L6o
{ =upeRY@u5
int n = -1; u^@f&BIG]:
try{ }eCw6
oSavedFile.write(b,nStart,nLen); H%qsjB^
n = nLen; 1gL2ia
} "jeb%k
catch(IOException e) j/323Za+
{ `uv2H$
e.printStackTrace (); ?8npG]L)
} tU}h~&M
132{#tG]
}|0^EWL
return n; 2J7:\pR^
} %aG5F}S2~
9vuyv*-}e
g/ T
} %".HaI]
[L3=x;U
hci6P>h<ia
/* ? &o2st
**SiteInfoBean.java pA'4|ffwe
*/ fx41,0;gZq
package NetFox; b z`+k,*
B nFwlw
1{)5<!9!l
public class SiteInfoBean { K[I=6
N]>=p.#j
5kc/Y/4o
private String sSiteURL; //Site's URL z`.<U{5
private String sFilePath; //Saved File's Path Sj%u)#Ub
private String sFileName; //Saved File's Name C)um9}
private int nSplitter; //Count of Splited Downloading File faEt6
Go5J%&E9
TH%Qhv\]
public SiteInfoBean() 0IsPIi"7
{//nSplitter的缺省值为5 .?8;qA
//default value of nSplitter is 5 wcrCEX=I>{
this("","","",5); Q:2>}QgX}
} /C:Y94B-z
u 1>2v
wT6"U$cV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pj\u9 L_
{ du<tGsy
sSiteURL= sURL; [g7L&`f9
sFilePath = sPath; g;H=6JeG/
sFileName = sName; ^h(ew1:
this.nSplitter = nSpiltter; t|w_i-&b,
Km qMFB62
m(r,Acy6
} =:xW>@bh|
+%+tr*04O
[`ebM,W
public String getSSiteURL() l.q&D< _
{ vLv@&lMW
return sSiteURL; kjTduZ/3"
} u0JB\)(-/h
UFXaEl}R
B{QBzx1L9c
public void setSSiteURL(String value) %6|nb:Oa
{ 5MroNr
sSiteURL = value; H9'$C/w
} 8H%;WU9-
iN bIp"W
}5ret
public String getSFilePath() +5w))9@
{ D>`xzt'.6
return sFilePath; /j#n
} .M qP_Z',
@CpfP;*{w`
JB%',J
public void setSFilePath(String value) "|x^|n8i
{ %v=*Wb\3|
sFilePath = value; =ElO?9&
} Y4J3-wK5
|)IlMG
dH;8mb|#'
public String getSFileName() ~uj#4>3T
{ ,1y@Z 5wy
return sFileName; {kA0z2Fe
} Yk'XGr)
y`L>wq,KU
Lm iOhx
public void setSFileName(String value) 0CZ:Bo[3
{ g{7.r-uu
sFileName = value; AuvkecuIh
} MU($|hwiL
_('=b/
.eS<Dbku<
public int getNSplitter() Z_LFIz*c
{ ^P[e1?SZG
return nSplitter; g?c xp+
} NN%*b yK
4.k0<
?k+xSV
public void setNSplitter(int nCount) [u =+3b
{ ;0Q4<F
nSplitter = nCount; DHyq^pJ
} qSM|hHDo)
} cutuDZ
Q$a{\*[:+
U'k*_g
/* 6]&OrS[
**Utility.java .6ylZ
*/ TtJH7
package NetFox; 9)h"-H;5:
)cX*I gO
Ab~3{Q]#
public class Utility { 9"N~yKa`"K
B~'vCuE
&pP;Neh;
public Utility() 7!$Q;A
{ |T<_5Ik
c/:b.>W
~Zun&b)S
} /74QMx?
;nI] !g:
//线程睡眠 F3y9@dA]
public static void sleep(int nSecond) S50k>_a;
{ zUt'QH7E.
try{ EB0TTJR?#
Thread.sleep(nSecond); g1;:KzVv
} ^+*N%yr
catch(Exception e) 5 )A1\
{ ,L|%"K]yM
e.printStackTrace (); t*=CZE-
} @#l `iK
} w_aknt T
03L]
//日志 DRSr%d
public static void log(String sMsg) RaO-H
{ MOQ6:
System.err.println(sMsg); |-b#9JQ[A
} 4`lLf
[xbSYu,&
`:ArT}F
public static void log(int sMsg) $r^GE
{ On8v//=&
System.err.println(sMsg); "x#-sZ=
} +UCG0D
} T tfo^ksw
eJrQ\>z]V&
oro$wFxJO
/* ~Sdb_EZ
**TestMethod.java loEPr5bL
*/ 5A,K6f@:g
package NetFox; ,j#XOy`mzy
R]JT&p|w.1
,A9]CQ
public class TestMethod { hE &xE;
>d(~#Z`
EW}Bzh>b
public TestMethod() ##q2mm:a9P
{ ///xx/weblogic60b2_win.exe zU,9T
try{ 3Lfqdqj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SDC4L <!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R1s`z|?
SiteFileFetch fileFetch = new SiteFileFetch(bean); AKY1o.>z
fileFetch.start(); Mhm@R@
} w{{gu1#]G
catch(Exception e){e.printStackTrace ();} .nO\kgoK
d}Xr}
fIM,lt
} )n1_(;
/~DI 6g
FX;QG94!
public static void main(String[] args) O5!7'RZ
{ _;W.q7b]
new TestMethod(); {k(g]#pP
} @g|v;B|{
} u/UrAqw
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