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)); e8)8QmB{o
} u X(#+
for(int i=0;i<nEndPos.length-1;i++) kM76?M
{ o4YF,c+>q
nEndPos = nStartPos[i+1]; ]QF*\2b-I2
} $KsB'BZy
nEndPos[nEndPos.length-1] = nFileLength; 8y]{I^z}
} .h@bp1)l
} U;Yw\&R,
x!fRT.,}
+"VXw2R_e
//启动子线程 ~01t_Xp qc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [4mIww%
for(int i=0;i<nStartPos.length;i++) W"D>>]$|u
{ ~mT([V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p7,dl*'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q)RTy|NJ^
nStartPos,nEndPos,i); %)y-BdSp.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fLuOxYQbf
fileSplitterFetch.start(); )24 1-b V
} + $Lc'G+:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rab7Y,AA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F441K,I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xp]_>WGq
nEndPos = " + nFileLength); hhJs$c(
// fileSplitterFetch[nPos.length-1].start(); ^:ehG9
&hIr@Gi@ch
(l)r.Vj
//等待子线程结束 VW**N}1#C
//int count = 0; *,Sa*-7(
//是否结束while循环 S8;5|ya
boolean breakWhile = false; |p*s:*TJp
3/CKy##r%]
7"Q;Yi2(
while(!bStop) b5l;bXp]
{ <1kK@m -E
write_nPos(); I=7 YAm[W
Utility.sleep(500); 35~1$uRA
breakWhile = true; 28lor&Cc
#!w7E,UBi
v3r<kNW_
for(int i=0;i<nStartPos.length;i++) d-B,)$zE
{ @E?o~jO(e
if(!fileSplitterFetch.bDownOver) &xS] ;Fr
{ mz3Dt>
breakWhile = false; =m?x5G^
break; 9*? i89T
} ?Nl@K/
} {br6*
if(breakWhile) y2>AbrJ
break; le~p2l#e
17!<8vIV$C
OsgjSJrf
//count++; "E7YCZQR
//if(count>4) A7zL\U4
// siteStop(); nZ#0L`@"Y
} _O`s;oc
JQA]O/|N
P u,JR
System.err.println("文件下载结束！"); +?GsIp@>jh
} {A{sRT=%
catch(Exception e){e.printStackTrace ();} N"zm
} J|DY /v
_kUtj(re
t:tIzFNv
//获得文件长度 nRheByYm
public long getFileSize() vFi+ExBU
{ $u::(s} x<
int nFileLength = -1; mN1n/LNi
try{ c{})Z=
URL url = new URL(siteInfoBean.getSSiteURL()); hfRxZ>O2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0!q@b
httpConnection.setRequestProperty("User-Agent","NetFox"); i: VMCNH
IkgRZ{Y
`4a9<bG
int responseCode=httpConnection.getResponseCode(); v}Kj+9h
if(responseCode>=400) dg@'5.ApPu
{ X`fer%`
processErrorCode(responseCode); 6~a4-5;>z
return -2; //-2 represent access is error Pr#uV3\
} }EN-WDJD\
!OMl-:KUzE
/2:s g1
String sHeader; 1( rN
<4.j]BE
3NN)ql
for(int i=1;;i++) sQLjb8!7
{ 75H;6(7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qR9!DQc'
//Utility.log(in.readLine()); uevhW
sHeader=httpConnection.getHeaderFieldKey(i); Xt$Y&Ho
if(sHeader!=null) 0G(|`xG1q
{ *fQn!2}=(
if(sHeader.equals("Content-Length")) RdLk85<n
{ `':G92}#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OF O,5
break; NwNjB w%v
} g\G}b
} @J<RFgw#
else &L r~x#Wx
break; ]+T$D
} QQ./!
} f;obK~b[
catch(IOException e){e.printStackTrace ();} 4,?WNPqo
catch(Exception e){e.printStackTrace ();} O<y65#68Z
SL?YU(a
!>)o&sM
Utility.log(nFileLength); * 5(%'3
TPNKvv!s
ma@!"Z8S
return nFileLength; JHg y&/
} t/h,-x
Sgn<=8,6c
+3]V>Mv
//保存下载信息（文件指针位置） ln_[@K[oX
private void write_nPos() a.fdCI]%
{ '8;'V%[+
try{ Pdk#"H-j
output = new DataOutputStream(new FileOutputStream(tmpFile)); q5\iQ2f{WV
output.writeInt(nStartPos.length); #E#Fk3-ljQ
for(int i=0;i<nStartPos.length;i++) !k!1h%7q
{ $ U-#woXa
// output.writeLong(nPos); 5'n$aFqI
output.writeLong(fileSplitterFetch.nStartPos); VI?kbqjo
output.writeLong(fileSplitterFetch.nEndPos); "&@{f:+
} K<MWiB&
output.close(); =LKf.@]#
} >FqU=Q
catch(IOException e){e.printStackTrace ();} B{>x
catch(Exception e){e.printStackTrace ();} 4++pK;I
} =-/sB>-C
;3+_aoY
I6PReVIb
//读取保存的下载信息（文件指针位置） qD,/Qu62
private void read_nPos() )&qr2Cm*
{ sCE%./h]
try{ g1)ZjABV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {TaYkuWS
int nCount = input.readInt(); F[>Y8e<[
nStartPos = new long[nCount]; nBwDq^
nEndPos = new long[nCount]; D+{&zo
for(int i=0;i<nStartPos.length;i++) ~#7uNH2
{ H/ar:j
nStartPos = input.readLong(); |mT1\O2a
nEndPos = input.readLong(); o^b5E=?>C
} >tm4Rg~y
input.close(); PCnu?e3F
} me$nP}%C&
catch(IOException e){e.printStackTrace ();} wxy@XN"/i+
catch(Exception e){e.printStackTrace ();} a&u!KAQ
} %uvA3N>
B(Er/\-@U
HJt '@t=Ak
private void processErrorCode(int nErrorCode) ,>Dpt<
{ }H|'W[Q.
System.err.println("Error Code : " + nErrorCode); F12$BKDH
} 5-UrHbpCZ#
kc<5wY_t
lLLPvW[Q
//停止文件下载 ?*'0;K13
public void siteStop() K?>sP%m)
{ u@t~*E5BpM
bStop = true; YI2x*t!
for(int i=0;i<nStartPos.length;i++) <Df2
fileSplitterFetch.splitterStop(); \=Od1i
8L5O5F'
gObafIA
} {+V ]@sz
} 3!`_Q%
//负责部分文件的抓取 ~/rKKc
**FileSplitterFetch.java nK#%Od{GF
*/ c[Z#q*Q
package NetFox; G|TnvZ KX
JH*fxG
o $'K}U
import java.io.*; 0S$TLbx
import java.net.*; nX8ulGGs
eo^C[# .
L.8`5<ITw
public class FileSplitterFetch extends Thread { uw(Ml=
Gh352
,s/laZ)V
String sURL; //File URL FcyFE~>2
long nStartPos; //File Snippet Start Position 8~3I^I_v
long nEndPos; //File Snippet End Position G+<id1
int nThreadID; //Thread's ID ??lsv(v-
boolean bDownOver = false; //Downing is over Q=Liy@/+!
boolean bStop = false; //Stop identical o>|DT(Ib
FileAccessI fileAccessI = null; //File Access interface 8+H 0
H~bbkql
H3( @Q^9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6W:FT Pt44
{ tl`x/
this.sURL = sURL; zR)/h
this.nStartPos = nStart; tToP7q^
this.nEndPos = nEnd; \UZ7_\
nThreadID = id; @76I8r5l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^fmuBe}d{
} $i1:--~2\
G!o6Y:1!
I@TH^8(
public void run() \["I.gQ
{ Wl}J=
while(nStartPos < nEndPos && !bStop) ;te( {u+
{ 0[ (kFe
@U@O#+d'ZR
`26.+>Z7
try{ M*D@zb0ia
URL url = new URL(sURL); )Br#R:#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x=kJlGT
httpConnection.setRequestProperty("User-Agent","NetFox"); 9 9^7Ek!z#
String sProperty = "bytes="+nStartPos+"-"; g |H
httpConnection.setRequestProperty("RANGE",sProperty); n3j_=(
Utility.log(sProperty); lgZ9*@d
>< VUly
')/w+|F
InputStream input = httpConnection.getInputStream(); G ]uz$V6!
//logResponseHead(httpConnection); | GN/{KH]
#g'j0N
y>7 r;e
byte[] b = new byte[1024]; |~&cTDd
int nRead; Q<KF<K'0hg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zr=B8wuT
{ 9e.$x%7j
nStartPos += fileAccessI.write(b,0,nRead); W|"bV 6d3
//if(nThreadID == 1) Rt5pl,Nf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T#i~/
} <PM.4B@
fxmY,{{
$4qM\3x0,
Utility.log("Thread " + nThreadID + " is over!"); ]9c{qm}y
bDownOver = true; c *<m.
//nPos = fileAccessI.write (b,0,nRead); %@|)&][hO
} u:tcL-;U
catch(Exception e){e.printStackTrace ();} _!Pi+l4p/}
} 4wGBB{X
} )>"pm{g2
2%9L'-
h:sf?X[
//打印回应的头信息 ii>^]iT
public void logResponseHead(HttpURLConnection con) rBi6AM/
{ R%q:].
for(int i=1;;i++) YB!f=_8
{ Qwve-[
String header=con.getHeaderFieldKey(i); 4mtO"'|
if(header!=null) fEiNHVx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]w0Y5H "
Utility.log(header+" : "+con.getHeaderField(header)); {47Uu%XT
else +$#XV@@~
break; aof'shS8
} b5I 8jPj4c
} gm=C0Sp?
_8-T?j**
/3VO!V]u
public void splitterStop() PgHmOs
{ Qr7|;l3
bStop = true; ,4 q^(
} 27,c}OS5o
7I@df.rf6J
{u9n?Z%
} IXlk1tHN4I
BE],PCpPr
0c1=M|2
/* 8~~ k?
**FileAccess.java ,-8Xb+!8I
*//文件访问(定位，写) y?A*$6
package NetFox; ksOc,4A
import java.io.*; R y(<6u0
B&<5VjZ\
%tC[q
public class FileAccessI implements Serializable{ Xwjm T
w=: c7Y+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'o*\N%
RandomAccessFile oSavedFile; q/Ji}NGm
long nPos; nEW.Y33
[*I7^h%
DiY74D
public FileAccessI() throws IOException CfD4m,6
{ FP7N^HVBG=
this("",0); #<U@SMv
} b$_qG6)IJO
O '`|(L
<eP,/H
public FileAccessI(String sName,long nPos) throws IOException Uovna:"
{ qm'@o -[
oSavedFile = new RandomAccessFile(sName,"rw"); 9}Za_ZgG
this.nPos = nPos; @g]+$Yj
oSavedFile.seek(nPos); \2#K {
} /~7M @`1
mG@[~w+
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public synchronized int write(byte[] b,int nStart,int nLen) -*hPEgcV9
{ |9Yx`_DF
int n = -1; l-!"
try{ KK]R@{ r
oSavedFile.write(b,nStart,nLen); l@u "iGw
n = nLen; 6W3."};
} +lZ-xU1
catch(IOException e) Eza^Tbq%j?
{ AE`UnlUSF
e.printStackTrace (); n "^rS}Y]
} 1vCp<D9<
HZS.%+2
m!!;CbPo
return n; 6 b?K-)kL
} R/Sm
*f{4_ts
,KF>@3f
} 6 OvH"/X4
zlTLp-^Y
SB5qm?pT8<
/* yd'cLZd<}
**SiteInfoBean.java B#.xs>{N
*/ H4{7,n
package NetFox; 'O9Yu{M
DYC2bs>
UEm4):/}
public class SiteInfoBean { g2*}XS3
$P#+Y,r~\
xB?!nd
private String sSiteURL; //Site's URL @{Fa=".Ch
private String sFilePath; //Saved File's Path l&"bm C:xr
private String sFileName; //Saved File's Name v&%W*M0q@
private int nSplitter; //Count of Splited Downloading File xdY'i0fh
I$)9T^Ra
wdV)M?
public SiteInfoBean() 0"+QWh
{//nSplitter的缺省值为5 QJ>=a./
//default value of nSplitter is 5 cIkA ~F
this("","","",5); UYQ@ub
} /k^j'MMQs6
R`@7f$;wG
a8%T*mk(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +|K,\ {'U
{ 8{{^pW?x
sSiteURL= sURL; p;R&h4H
sFilePath = sPath; {l_D+B;
sFileName = sName; ;eO Ye3;c
this.nSplitter = nSpiltter; LW("/
kI5LG6
3W.D^^)eCV
} Z3ODZfu>
W=|'&UU Ul
XuZgyt"=r
public String getSSiteURL() >s,*=a
{ Pl#u,Y
return sSiteURL; a{%EHL,F
} U~c9PqjZ
R iV]SgV9
_+}hId
public void setSSiteURL(String value) YhAO
{ rEU1 VvE
sSiteURL = value; ;;U&mhz`
} ZX{eggXl
Ls.g\Gl3
|c-`XC2g
public String getSFilePath() C)9-{Yp
{ gq~`!tW'
return sFilePath; ]x3 )OjH
} AP=SCq;
cmaha%3d
qPhVc9D#
public void setSFilePath(String value) AO5a
{ HJ!)&xT
sFilePath = value; @OHNz!Lj:d
} 'Nx"_jQ
[r'hX#
x0TE+rf5
public String getSFileName() wc~9zh
{ E!I4I'
return sFileName; .Dr7YquW
} v yP_qG
td#m>S
l|9'l[}&
public void setSFileName(String value) f\~w!-
{ xu;^F
sFileName = value; }ASBP:c"t
} kll,^A
/T6Te<68^
% %2~%FVb
public int getNSplitter() u/\Ipk/
{ otP2qAI
return nSplitter; )S_%Ip
} )MX%DQw
r&L1jT.
Vr&v:8:wb
public void setNSplitter(int nCount) pcm1IwR`
{ qEkhgJqk
nSplitter = nCount; Ac[;S!R
} x_H"<-By
} !W=2ZlzS
vha@YPC=
A{')
/* I+Fr#1
**Utility.java \}Pr!tk!
*/ )9!ZkZbv_m
package NetFox; a$6pA@7}
wo^1%:@/2
^$lsmF]^
public class Utility { o`}8ZtD
2TaHWw<A
hrOp9|!m
public Utility() O}7aX '
{ \l 3M\$oS>
`k08M)
TR{dNO!q
} N=:xyv
B_.>Q8tK;
//线程睡眠 WS$~o*Z8
public static void sleep(int nSecond) +Pn`AV1
{ b55G1w
try{ .:, 9Tf
Thread.sleep(nSecond); @jD19=
} j7HOh|q
catch(Exception e) "QY~V{u5
{ jH4Wu`r;m
e.printStackTrace (); 9p"';*{=
} m$q*
} WF<*rl
+Nka,C^O"
//日志 ;!>>C0s"
public static void log(String sMsg) /3~}=b
{ sZU Ao&
System.err.println(sMsg); tLx8}@X"
} h6(L22Hn
^#2Y4[@
*km- pp
public static void log(int sMsg) jY\YSQ
{ vYG$>*
System.err.println(sMsg); Aj=c,]2
} R~BW=Dz,e
} W{;LI WsZ
d _koF-7
>Q^*h}IdW
/* \Ng[lN
**TestMethod.java \V.U8asfI
*/ e9?y0vT//
package NetFox; rHgrCMW
9'JkLgz;d+
DzCb'#
public class TestMethod { cGjkx3l*
eD 7Rv<
Z?'){\$*
public TestMethod() `#N7ym;s@
{ ///xx/weblogic60b2_win.exe (fWQ?6[
try{ \[x4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BRMR> ~k(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C/pu]%n@4
SiteFileFetch fileFetch = new SiteFileFetch(bean); cV)~%e/
fileFetch.start(); GD .>u
} 93#wU})
catch(Exception e){e.printStackTrace ();} MMUw+jM4
Ehf{Kl
[p_C?hHO
} (*YENT}
ZpY"P6
rk(0w|zR+
public static void main(String[] args) FKB)o7
{ >pA9'KWs]
new TestMethod(); Q /\Hc
} K?+Rq
} `{I-E5x
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