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)); (zwxrOS
} O`g44LW2n
for(int i=0;i<nEndPos.length-1;i++) i{I'+%~R
{ Xnt`7L<L
nEndPos = nStartPos[i+1]; BLgmFE2
} f7)}A/$4+
nEndPos[nEndPos.length-1] = nFileLength; &"BmCDOq
} ?=dyU(
} v:PNt#Ta
ELk$lm&@
aAh")B2
//启动子线程 c|X.&<lX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q@~N?$>
for(int i=0;i<nStartPos.length;i++) 57Y(_h:
{ :iD([V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y)t< r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yd]W',c
nStartPos,nEndPos,i); _*0!6?c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w{#K.dx
fileSplitterFetch.start(); F2:+i#lE
} ;El"dqH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )a.w4dH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;26a8g(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O(!J^J3_z
nEndPos = " + nFileLength); -_[n2\|we)
// fileSplitterFetch[nPos.length-1].start(); dB ?+-aE
G5|xWeNgA
N8m|Y]^H#
//等待子线程结束 ld-c?
//int count = 0; 5u'"m<4
//是否结束while循环 eh2w7@7Q
boolean breakWhile = false; ,DqI> vx|
U;Se'*5xv
HDvj{
while(!bStop) H^_[nL
{ .t.H(Q9
write_nPos(); 3;Kv9i<~LE
Utility.sleep(500); X3tpW`alo
breakWhile = true; %L.,:mtq)
)?^0<l#s
}\|$8~
for(int i=0;i<nStartPos.length;i++) Lfx&DK !
{ (5]<t&M
if(!fileSplitterFetch.bDownOver) F8$.K*tT
{ M&Sjo' ( .
breakWhile = false; h`-aO u
break; poGF
} lsU|xOB
} MLtfi{;LH
if(breakWhile) jY-{hW+r
break; 6AKH0t|4
u3(zixb
Q@6OIE
//count++; G4{ zt3{
//if(count>4) zGHP{a1O7
// siteStop(); j!B+Q
} Bf~
U=\ZeYK.
|GM?4'2M.
System.err.println("文件下载结束！"); G&)A7WaC
} H{ p
catch(Exception e){e.printStackTrace ();} ;| ##~Y.9
} T~J6(,"
&Ey5 H?U!
-'QvUHL|
//获得文件长度 Ac0C,*|^
public long getFileSize() mw!D|
{ $YSAD\a<
int nFileLength = -1; )WF]v"t
try{ e7T"?s
URL url = new URL(siteInfoBean.getSSiteURL()); cq>{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P95U{
httpConnection.setRequestProperty("User-Agent","NetFox"); 2>Hl=bX
=hxj B*")
;XNe:g.CR
int responseCode=httpConnection.getResponseCode(); 0%+S@_|
if(responseCode>=400) dnTB$8&
{ #56}RV1
processErrorCode(responseCode); Eqc&iS~
return -2; //-2 represent access is error TCYjj:/
} -lV]((I&
G7yCGT)vQ
h}k&#X)7
String sHeader; Eo 5p-
f=]+\0MQ
Pc#8~t}2
for(int i=1;;i++) Ox7v*[x'
{ "aIiW VQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); td%]l1
//Utility.log(in.readLine()); VC5LxA0{
sHeader=httpConnection.getHeaderFieldKey(i); j9)P3=s
if(sHeader!=null) NNLZ38BV7
{ :0|]cHm
if(sHeader.equals("Content-Length")) 3`uv/O2~i
{ secD `]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _TfG-Ae
break; |=L~>G
} jq:FDyOAW
} F$QN>wPpM
else B{$4s8XU
break; wi^zXcVj
} eQ`TW'[9_6
} 0O<g)%Vz>
catch(IOException e){e.printStackTrace ();} xpCzx=n3.m
catch(Exception e){e.printStackTrace ();} +EjH9;gx
Q]]}8l2
<@6K(
Utility.log(nFileLength); 3>YG
SxMmy
Vp{! Ft8>
return nFileLength; A:PQIcR;V
} Wd#r-&!6j
/tR@J8pV
"| cNY_$&s
//保存下载信息（文件指针位置） d 4w+5H"u
private void write_nPos() FDBj<uXfM|
{ ts%XjCN[
try{ 7s@%LS
output = new DataOutputStream(new FileOutputStream(tmpFile)); WP[h@#7<
output.writeInt(nStartPos.length); 4>eY/~odq]
for(int i=0;i<nStartPos.length;i++) !)gTS5Rh:
{ B64L>7\>`
// output.writeLong(nPos); ,<R/jHZP9
output.writeLong(fileSplitterFetch.nStartPos); 0NrUB
output.writeLong(fileSplitterFetch.nEndPos); C1&~Y.6m
} DuX7
output.close(); {`?C5<r
} `>KB8SY:qK
catch(IOException e){e.printStackTrace ();} 95LZG1]Rb
catch(Exception e){e.printStackTrace ();} =?g26>dYo
} Z-X(.Q
H8.Aq\2S
k+#6
//读取保存的下载信息（文件指针位置） ;D.a |(Q
private void read_nPos() $I*ye+a*{q
{ :cU6W2EV
try{ I/4:SNha
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "2}{lu
int nCount = input.readInt(); <%w)EQf4m
nStartPos = new long[nCount]; s|B
nEndPos = new long[nCount]; eGcc'LBr;
for(int i=0;i<nStartPos.length;i++) F]o&m::/K
{ SNqw2f5
nStartPos = input.readLong(); ;[@);-9q
nEndPos = input.readLong(); q)0?aL
} 4)MKYhm
input.close(); =)_9GO
} A+Uil\%
catch(IOException e){e.printStackTrace ();} *nJy
catch(Exception e){e.printStackTrace ();} 6[3oOO:uo
} \yt-_W=[
E57:ap)/
ffyDi1Q
private void processErrorCode(int nErrorCode) );EW(7KeL
{ XG_h\NIL
System.err.println("Error Code : " + nErrorCode); %]NaHf
} PNy)TqdRS
.axJ'*~W
dJyf.VJ
//停止文件下载 X*f#S:kiNU
public void siteStop() C>l{_J)n
{ ' cM2]<
bStop = true; T%0vifoQ_$
for(int i=0;i<nStartPos.length;i++) o[Ojl.r<
fileSplitterFetch.splitterStop(); v C,53g
p5F=?*[}
iA*^`NMaT
} ^na8d's:
} ]?KTw8j}
//负责部分文件的抓取 WRa1VU&f
**FileSplitterFetch.java Fu0"Asxce
*/ `y"(\1
package NetFox; Dxp8^VL
f};lH[B3y
> mI1wV[
import java.io.*; dL{zU4iUR
import java.net.*; 7b>FqW)%
aC$-riP,?'
Y]>!uwn
public class FileSplitterFetch extends Thread { '+?L/|'
6<aZr\Ufg
4#<r}j12z
String sURL; //File URL hd+(M[C<9
long nStartPos; //File Snippet Start Position `N;}Gf-'
long nEndPos; //File Snippet End Position ( X(61[Lu
int nThreadID; //Thread's ID 5:S=gARz
boolean bDownOver = false; //Downing is over q{4W@Um-
boolean bStop = false; //Stop identical BY*{j&^
FileAccessI fileAccessI = null; //File Access interface $y%X#:eLJ
bcx,Kb
:mP%qG9U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }~B@Z\`O
{ h?t#ABsVK
this.sURL = sURL; ~nQ=iB
this.nStartPos = nStart; K<k!sh
this.nEndPos = nEnd; dyH<D5
nThreadID = id; ~H<oqk:O-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qW~Z#Si
} >WYiOXYv
6t zUp/O
^a>3U l{
public void run() eXs^YPi
{ _:N+mEF
while(nStartPos < nEndPos && !bStop) ub/Z'!
{ pr~%%fCh
)I~U&sT\/
o )\\(^ld
try{ h=?V)WSM
URL url = new URL(sURL); +/"Ws'5E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7hV9nuW
httpConnection.setRequestProperty("User-Agent","NetFox"); =2Vs))>Y
String sProperty = "bytes="+nStartPos+"-"; mGZJ$|
httpConnection.setRequestProperty("RANGE",sProperty); g=ehAg
Utility.log(sProperty); c#)!-5E~H
,)&ansN
/#<R
InputStream input = httpConnection.getInputStream(); sxG8jD
//logResponseHead(httpConnection); +,;"?j6<p
)Cas0~RM
c<k=8P
byte[] b = new byte[1024]; \@\r`=WgB
int nRead; 2wCSjAWWh(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JD\yl[ac%
{ o*]Tqx
nStartPos += fileAccessI.write(b,0,nRead); y nue;*rM
//if(nThreadID == 1) %|"0p3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EO.Se9ux
} B|\JGnNQ
m8jQ~OS
]VKM3[
Utility.log("Thread " + nThreadID + " is over!"); tfKf*Um
bDownOver = true; LqYP0%7
//nPos = fileAccessI.write (b,0,nRead); wOMrUWB0
} Tasmbo^mAF
catch(Exception e){e.printStackTrace ();} |\}&mBR
} w"PnN
} f6of8BOg
b(E}W2-t
^uWPbW&/q
//打印回应的头信息 %#_"Ie
public void logResponseHead(HttpURLConnection con) Pv#Oea?
{ m{v*\e7P
for(int i=1;;i++) @V\u<n
{ $a@T:zfe
String header=con.getHeaderFieldKey(i); v3*y43
if(header!=null) ZXJ]==
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |>Ld'\i8
Utility.log(header+" : "+con.getHeaderField(header)); Mzg zOM
else Za110oF
break; ~M c'~:{O
} ]NEr]sc-"F
} cD%_+@GaU
S|jE1v"L
L2sUh+'|
public void splitterStop() o^efeI
{ gTM*td(~^
bStop = true; [ pe{,lp
} 7^oO N+=d
|#b]e|aP
+nIjW;RU
} < NRnE8:
iJ&jg`"=F
P Nf_{4
/* OGR2Y
**FileAccess.java SzTa[tJ+
*//文件访问(定位，写) 2FVO@D
package NetFox; "y9]>9:$-
import java.io.*; X7~^D[X
XsEotW
3LkcK1x.
public class FileAccessI implements Serializable{ De-hHY{>
gX%"Ki7.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6(1S_b=a
RandomAccessFile oSavedFile; ?Tlt(%f
long nPos; u\AL`'v
7WMF8(j5
-u$U~?|`
public FileAccessI() throws IOException {aVRvZH4
{ Nd h
this("",0); 6/3oW}Oo
} W]W[oTJ5
A"}Ib'
&}rmDx
public FileAccessI(String sName,long nPos) throws IOException Z}AhDIw!G
{ $~,J8?)(z
oSavedFile = new RandomAccessFile(sName,"rw"); 2CF5qn}T
this.nPos = nPos; U^;|as
oSavedFile.seek(nPos); )z_5I (?&
} <\'aUfF v
QPyHos`
dJ9v/k_
public synchronized int write(byte[] b,int nStart,int nLen) Y6[O s1
{ m S4N%Q
int n = -1; /8? u2 q
try{ h J H
oSavedFile.write(b,nStart,nLen); tch;_7?
n = nLen; M{jJ>S{g
} 4M)oA|1w
catch(IOException e) $vLGX>H
{ 98rO]rg
e.printStackTrace (); }rQ0*h
} JKF/z@Vbe\
"!9FJ Y
U1)!X@F{
return n; =&"a:l
} ,ll<0Atg
@b9qBJfQ
7NMy1'-q
} }3/|;0j$
6n:oEXM>
ILIv43QKM(
/* A D%9;KQ8
**SiteInfoBean.java vhGX&
*/ UZ;FrQ(l{
package NetFox; =lmelo#m&
_)Ad%LPsd7
^Z+p_;J$p
public class SiteInfoBean { w y&yK*w
GOUO
" V4@nv
private String sSiteURL; //Site's URL N5b^
private String sFilePath; //Saved File's Path 'x,6t66*"l
private String sFileName; //Saved File's Name hiEosI C
private int nSplitter; //Count of Splited Downloading File 5p>rQq0
;--p/h*.
Hbl&)!I
public SiteInfoBean() .1f!w!ltVR
{//nSplitter的缺省值为5 7po;*?Ox
//default value of nSplitter is 5 \HL66%b[
this("","","",5); RN2z/FUf
} G2dPm}sZG
pD]2.O
@GWlo\rM6^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zgl$ n
{ |F +n7
sSiteURL= sURL; .\+c{
sFilePath = sPath; 6Z5$cR_vC7
sFileName = sName; `0`#Uf_/$
this.nSplitter = nSpiltter; pQoZDD@B$
t9r R>Y9
T>irW(
} N>w+YFM
gNC'kCx0c
;;N#'.xD
public String getSSiteURL() blUS6"kV}
{ NNBT.k3)
return sSiteURL; [W99}bi$
} rAk;8)O$
AZ SaI
gZ us}U
public void setSSiteURL(String value) #n+sbx5~7
{ Of#"nu
sSiteURL = value; tm.&k6%
} p.5 *`, )
_6->D[dB
]}pAZd
public String getSFilePath() :BF WX
{ _TyQC1 d
return sFilePath; iV:\,<8d
} AD>/#Ul
9hgIQl
1[-RIN;U8
public void setSFilePath(String value) rIX 40,`
{ !Pu7%nV.
sFilePath = value; \==Mgy2J8
} r;O?`~2'4
M"foP@
Mo]iVj8~
public String getSFileName() }Qh%Z)
{ knzQ)iv&&
return sFileName; ]''tuo2g8
} bd3>IWihp
#fFD|q
qnzNJ_ `R
public void setSFileName(String value) Q'[~$~&`
{ ?sxf_0*
sFileName = value; I#xhmsF
} GYonb)F
OkphbAX
h1#l12k^'
public int getNSplitter() U+uIuhz
{ OA7=kH@3c
return nSplitter; %5;kNeD\Fq
} Up>,~bs]
#+^l3hMK
)5TX3#=;(G
public void setNSplitter(int nCount) (A;HB@)[A
{ mG%cE(j*D
nSplitter = nCount; [n +(
} cGWL'r)P
} {XW>3 "
7N0m7SC
#Z]<E6<=9
/* -./Y
**Utility.java xG(:O@
*/ z]sQ3"cmX
package NetFox; tAb3ejCo?
O>ZJOKe
&<hk&B
public class Utility { !)c0
|\]pTA$2
/sl#M
public Utility() TSsx^h8/
{ "?YpF2pD
'IER9%V$
wDs#1`uTq
} ~'):1}KN]
'v@1_HHW\
//线程睡眠 ;e~K<vMm;y
public static void sleep(int nSecond) o#IWH;ck.
{ ,-> P+m5
try{ &HJ~\6r\
Thread.sleep(nSecond); JM*rPzp
} *JaFt@ x
catch(Exception e) C,u;l~zz
{ .|K\1qGW0
e.printStackTrace (); uMBb=
} *1}vn%wvn
} ^N~Jm&I
:wJ!rn,4
//日志 SHCVjI6
public static void log(String sMsg) T f^O(
{ 16I(S
System.err.println(sMsg); B^1Io9
} GF Rd:e
||?wRMV
OL[_2m*;9p
public static void log(int sMsg) q{.~=~
{ %;G!gJeE
System.err.println(sMsg); yNQ 9~P2
} N?Ss/by8Sg
} Os1y8ui
`RE1q)o}8M
dGc>EZSdj
/* 5xG/>fn
**TestMethod.java !Jo.Un7
*/ *Xd_=@L&B
package NetFox; O0"&wvR+5
i)e)FhEY6
O11.wLNH
public class TestMethod { v aaZ
upH%-)%'
/XW,H0pR
public TestMethod() 2qkC{klC^M
{ ///xx/weblogic60b2_win.exe o6;VrpaNi
try{ GG_A'eX:I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?Qs>L~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o=(>#iVM
SiteFileFetch fileFetch = new SiteFileFetch(bean); [ \Aor[(
fileFetch.start(); Z8Clm:S
} AwL;-|X
catch(Exception e){e.printStackTrace ();} 3!B3C(g
HjN )~<j
6_a.`ehtj<
} 5(OF~mX#
~ .Eln+N
|m7`:~ow
public static void main(String[] args) v6?<)M%
{ @)8C
new TestMethod(); h-h}NCP
} Jh:-<xy)
} 3'2}F%!Mv
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