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)); LW{7|g
} 9V9K3xWn
for(int i=0;i<nEndPos.length-1;i++) _RST[B.u6
{ zL+jlUkE
nEndPos = nStartPos[i+1]; Gh>Rt=Qu%
} ~Yb5FYE
nEndPos[nEndPos.length-1] = nFileLength; |zKFF?7#wE
} `DUMTFcMX
} ,KdDowc
;vy"i
f)Z$,&
//启动子线程 9h9 jS~h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bd5\Rt
for(int i=0;i<nStartPos.length;i++) pi7W8y
{ :uSo2d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Uz} #.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AU OL?st
nStartPos,nEndPos,i); AD_")_B|i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zN:VT&
fileSplitterFetch.start(); Tuo`>ZA
} -B*= V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8Mf6*G#Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8LB,8*L^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J NPEyC
nEndPos = " + nFileLength); onI%Jl sq
// fileSplitterFetch[nPos.length-1].start(); iV58 m
; $i{>mDT
zogw1g&C
//等待子线程结束 hs!a'E
//int count = 0; &5h{XSv
//是否结束while循环 o:W>7~$jr=
boolean breakWhile = false; Ej~vp2
jAie[5
M ~zA
while(!bStop) !ow:P8K?
{ :k*'MU}
write_nPos(); {E@Fk,
Utility.sleep(500); LP-~;
breakWhile = true; HIsIW%B
.!e):&(8
2!Yq9,`
for(int i=0;i<nStartPos.length;i++) a\pOgIp
{ 'y[74?1
if(!fileSplitterFetch.bDownOver) ($pNOGH
{ ;|}N\[fk%]
breakWhile = false; K!Te*?b
break; 2Tec#eYe
} SR!EQ<
} _2xNio&
if(breakWhile) -K eoq
break; z6)b XL[f
*:gx1wd
t~]n"zgovz
//count++; rofj&{w
//if(count>4) `u$ Rd
// siteStop(); H=RzY-\a%
} X'Q?Mh
]Wr2IM
Z}#'.y\ f
System.err.println("文件下载结束！"); zisf8x7^W
} .ZQD`SRrI
catch(Exception e){e.printStackTrace ();} "{(|}Cds
} Q6)Wh6Cm
N-Fs-uB
h;cl+c|B
//获得文件长度 DB%}@IW"
public long getFileSize() -@L7!,j
{ <+Eu.K&
int nFileLength = -1; C@d*t?
try{ DcYL8u
URL url = new URL(siteInfoBean.getSSiteURL()); -:cBVu-m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `yF6-F
httpConnection.setRequestProperty("User-Agent","NetFox"); .j^tFvN~L
iZY4+ X
i<@"+~n~GK
int responseCode=httpConnection.getResponseCode(); X .,Lmh
if(responseCode>=400) W>TG!R 5
{ 0,~||H{
processErrorCode(responseCode); kb3>q($
return -2; //-2 represent access is error +q n[F70}
} Cm@rXA/
}?G([s56
nVB.sab
String sHeader; :j^IXZW
2qd5iOhX+
[x{z}rYH
for(int i=1;;i++) ]bxBo
{ ncTPFv H5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wN NXUW
//Utility.log(in.readLine()); @=_4i&]$
sHeader=httpConnection.getHeaderFieldKey(i); I;1W6uD=
if(sHeader!=null) |BGB60}]f
{ O|K-UTWH%
if(sHeader.equals("Content-Length")) MrjgV+P}[
{ 5"sd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +pUG6.j%
break; W4Z8U0co
} mR,w~wP
} dCA| )
else 9K!kU6Gh
break; .`p,pt;
} _E %!5u
} ;k?Z,M:
catch(IOException e){e.printStackTrace ();} CWBlDz
catch(Exception e){e.printStackTrace ();} LV2#w_^I
|7%has3"
[}$jO,H5r
Utility.log(nFileLength); #`]`gNB0Yg
ej91)3AO
j]HzI{7y
return nFileLength; :2t0//@X
} ='A VI-go5
<+y%k~("
"m#17J_
//保存下载信息（文件指针位置） K_!R
private void write_nPos() eI,'7u4q
{ i?wEd!=w
try{ T.(C`/VM
output = new DataOutputStream(new FileOutputStream(tmpFile)); A_e&#O
output.writeInt(nStartPos.length); /a,"b8
for(int i=0;i<nStartPos.length;i++) 2# 72B
{ Bnp\G h
// output.writeLong(nPos); UuS6y9@v
output.writeLong(fileSplitterFetch.nStartPos); dNu?O>=
output.writeLong(fileSplitterFetch.nEndPos); joz0D!-"#
} ^F)t>K$0m
output.close(); Mz7qC3Z
} knn9s0'Q
catch(IOException e){e.printStackTrace ();} nsL"'iQ
catch(Exception e){e.printStackTrace ();} v6U Gr4
} *{:Zdg'~E
5GK> ~2c(
'XJqh|G
//读取保存的下载信息（文件指针位置） LZtO Q__B)
private void read_nPos() &|-jU+r}B
{ ?B+]Ex(\B,
try{ ^HhV?Iqg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n\ 'PNB
int nCount = input.readInt(); bL`>#M_^
nStartPos = new long[nCount]; ;nq"jm
nEndPos = new long[nCount]; bvW3[ V
for(int i=0;i<nStartPos.length;i++) ,(i`gH{D
{ q2b>Z6!5
nStartPos = input.readLong(); 8vkCmV
nEndPos = input.readLong(); >,x&L[3
} 'yo-`nNFD
input.close(); $^e(?Pq
} 4A`U [r_>D
catch(IOException e){e.printStackTrace ();} P5KpFL`B
catch(Exception e){e.printStackTrace ();} 3xk-D &"
} Spu> ac
s6F0&L;N&
M3U?\g
private void processErrorCode(int nErrorCode) `]`S"W7&
{ U?%T~!
System.err.println("Error Code : " + nErrorCode); z"nMR_TTu
} HV&i! M@T
U5 ia|V
cG"wj$'w
//停止文件下载 *(s0X[-
public void siteStop() 00B,1Q HP
{ 82)%`$yZw[
bStop = true; e'yw8U5E/
for(int i=0;i<nStartPos.length;i++) g@'2 :'\
fileSplitterFetch.splitterStop(); DH7]TRCMZ)
tmd{Gx}c
+~>cAWZq_
} G#Kw6
} `>4"i+NFF8
//负责部分文件的抓取 \kZ@2.pN
**FileSplitterFetch.java $."DOZQ3U
*/ ekW#|
package NetFox; n8E3w:A-
+B[XTn,Cru
Q#F9&{'l
import java.io.*; ce3``W/H3
import java.net.*; ]eUD3WUe>q
4T6: C?V
0GW69 z
public class FileSplitterFetch extends Thread { 5yyc0UG
F}.R-j#
;}lsD1S:
String sURL; //File URL J%]5C}v \
long nStartPos; //File Snippet Start Position 1#3eY?Nb
long nEndPos; //File Snippet End Position ^-LnO%h?
int nThreadID; //Thread's ID n&!q9CR`
boolean bDownOver = false; //Downing is over ~Ede5Vg!!2
boolean bStop = false; //Stop identical #@' B\!<@=
FileAccessI fileAccessI = null; //File Access interface JXjH}C
^RE[5h6^q
L&KL]n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d/3bE*gr
{ 4B9D
this.sURL = sURL; n%;4Fm?
this.nStartPos = nStart; s{OV-H
this.nEndPos = nEnd; `z`=!1
nThreadID = id; `,O"^zR)z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VnqcpJ
} ?E,-P!&R
Scug wSB
Q,M,^_
public void run() r0wAh/J|
{ d;,Jf*x\
while(nStartPos < nEndPos && !bStop) B8unF=u
{ 0dIGX |e
.F'Cb)Z
Aj]/A
try{ Lf:#koaC
URL url = new URL(sURL); guVuO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yf[1?{iVo
httpConnection.setRequestProperty("User-Agent","NetFox"); beBv|kI4
String sProperty = "bytes="+nStartPos+"-"; ^;K"Y'f$
httpConnection.setRequestProperty("RANGE",sProperty); V$wbmz
Utility.log(sProperty); g:.LCF
^I9U<iNIL
^F qs,^~W
InputStream input = httpConnection.getInputStream(); \PD%=~
//logResponseHead(httpConnection); .:XXc
~1XC5.*-
nI4oQE
byte[] b = new byte[1024]; z0x^HDAeC
int nRead; ^?_MIS`4N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h@]{j_$u
{ CfO{KiM(2
nStartPos += fileAccessI.write(b,0,nRead); P'[ISGt
//if(nThreadID == 1) -aLM*nIoe
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fu{v(^
} vM-kk:n7f
y<*\D_J
A8QUfg@uK~
Utility.log("Thread " + nThreadID + " is over!"); k.})3~F-
bDownOver = true; nltOX@P-
//nPos = fileAccessI.write (b,0,nRead); U\W$^r,
} 1cx%+-
catch(Exception e){e.printStackTrace ();} TD-B\ @_
} P)LQ=b}V#;
} wz@[rMf
,gW$m~\
'"XVe+.O
//打印回应的头信息 P9R-41!
public void logResponseHead(HttpURLConnection con) |z8_]o+|r1
{ W4qnXD1n
for(int i=1;;i++) ^$mCF%e8H
{ 4`'Rm/)
String header=con.getHeaderFieldKey(i); dKP| TRd
if(header!=null) 4uH} SG[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RameaFX8
Utility.log(header+" : "+con.getHeaderField(header)); z8r?C
else @My RcC
break; &xvNR=K[`
} E:O/=cT
} e\O625
ADM!4L(s4}
P8H2v_)X&
public void splitterStop() SmRFxqtN
{ unRFcjEa
bStop = true; J7`;l6+Gb
} 4uh~@Lv
<IBUl}|\
*y(UI/c
} dQFUQ
Pf;RJeD
`Ba?4_>k
/* )iVuac]E++
**FileAccess.java TwF.UL@G%
*//文件访问(定位，写) [,;O$j}
package NetFox; ONZ(0H{ 1$
import java.io.*; ~]Av$S
_,v>P2)
AFeFH.G6Jr
public class FileAccessI implements Serializable{ (w+SmD
7<L!" 2VB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !s !el;G
RandomAccessFile oSavedFile; KNN$+[_;H4
long nPos; hD7vjg&Z
!HtW~8|:
J9f]=1`
public FileAccessI() throws IOException [g}0.J`_
{ :T>OJ"p
this("",0); a<]vHC7
} Ji1#>;&
wzmQRn;s
>I0 a$w
public FileAccessI(String sName,long nPos) throws IOException Jh36NE8r
{ 0W_u"UY$c
oSavedFile = new RandomAccessFile(sName,"rw"); 4H@7t,>
this.nPos = nPos; b7">IzAe
oSavedFile.seek(nPos); +VJyGbOcC
} W<TfDEEa
fN21[Jv3
]GsI|se
public synchronized int write(byte[] b,int nStart,int nLen) ay`R jT
{ bYX.4(R
int n = -1; <u1`o`|-
try{ % .ss
oSavedFile.write(b,nStart,nLen); '|*e4n
n = nLen; C[l5[DpH
} J l{My^I5
catch(IOException e) e2>AL
{ >5TXLOYZ
e.printStackTrace (); )4hA Fy6l
} \/nSRAk
-G'3&L4 D
]r%fAmj
return n; 3qDbfO[
} Ls3r( Tf
&m]jYvRc
Q4Qf/q;U
} k'sPA_|
_EP~PW#J
T.B7QAI. H
/* O%aHQL%Sz
**SiteInfoBean.java h2= wC.
*/ [@3.dd
package NetFox; b`Jsu!?{
W59xe&l
*o!#5c
public class SiteInfoBean { p;D {?H/
"ub0}p4V
(\wV)c9
private String sSiteURL; //Site's URL SLH;iqPT
private String sFilePath; //Saved File's Path x2/ciC
private String sFileName; //Saved File's Name ,w=u?
private int nSplitter; //Count of Splited Downloading File y@AUSh;
0HQTe>!
nU6UjC|3
public SiteInfoBean() Jp_ :.4
{//nSplitter的缺省值为5 O*n@!ye
//default value of nSplitter is 5 2E!Q5 l!j
this("","","",5); hvA|d=R(
} ~jz51[{v
aN6HO
dl`{:ZR S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )YZx]6\l)
{ w6-<HPW<S
sSiteURL= sURL; ~at:\h4:
sFilePath = sPath; 6?JvvS5
sFileName = sName; (B?ZUXM,
this.nSplitter = nSpiltter; t8.3
-[h|*G.J
0< }BSv
} d7:=axo,
g;7u-nP
"x0KiIoPk
public String getSSiteURL() zH#urF6<
{ glBS|b$\:
return sSiteURL; P{: 5i%qC
} 8,e%=7h_e
gr# |ZK.`
,#%I$
public void setSSiteURL(String value) VtGZB3
{ %u2",eHCB
sSiteURL = value; CT'#~~QB
} ft4hzmuzM
::-*~CH)
*D1vla8
public String getSFilePath() M 5`hMfg
{ +%K~HYN
return sFilePath; IlB*JJnl
} )HX(-"c
2h)Qz+|7
Q5sJ|]Bc
public void setSFilePath(String value) <\P `<
{ 'T;;-M3*
sFilePath = value; zw iS%-F
} p\.IP2+c
?0qP6'nWx
}d5~w[
public String getSFileName() k~fH:X~x
{ 7 y$a=+D i
return sFileName; oa`7ClzD
} ,R-aO= %
#wZH.i#
Qd>\{$N
public void setSFileName(String value) ,lFp4C
{ KleiX7
sFileName = value; ;kT~&.,y
} Iv*u#]{t
0s RcA-9
su3Wk,MLP
public int getNSplitter() k+Z2)j"
{ Jb-.x_Bf
return nSplitter; "b%FkD
} Z9Z\2t
nlaW$b{=
q>5j (,6F
public void setNSplitter(int nCount) M+:9U&>
{ {-%8RSK=<
nSplitter = nCount; iq,rS"
} $dA]GWW5A
} ]b:>7_la
:\y' ?d- Q
FW|_8q?}<
/* Z[eWey_
**Utility.java 2(m#WK7>F
*/ |"+Ufw^
package NetFox; `3@?)xa
l,zhBnD
i4nFjz
public class Utility { VKf&}u/
o$rF-?
Lw%_xRn)
public Utility() $48Z>ij?f
{ q'TIN{\.{
/ :6|)AW.{
e[0"x.gu
} p@[ fZj
;47z.i&T
//线程睡眠 !&NrbiuN
public static void sleep(int nSecond) O;|Cu7WU
{ &b7_%,Bx4
try{ c*(^:#"9
Thread.sleep(nSecond); <HzL%DX
} '2ZvK
catch(Exception e) JodD6;P
{ ;_2+Y^Qb
e.printStackTrace (); z?( b|v
} ;{q*
} -V;BkE76
0U H]
//日志 ODhq `?(N
public static void log(String sMsg) yMTO5~U{
{ kFV, Fg
System.err.println(sMsg); UL{J%Ze=~
} m<#12#D
%0N HU`j
G0Qw& mqF
public static void log(int sMsg) Vm>EF~r
{ >MYDwH
System.err.println(sMsg); fyA-*)oHv
} kMMgY?
} $i5J}
W>)0=8#\
%&| uT
/* R]iV;j|
**TestMethod.java ,1$F#Eh
*/ uMS+,dXy
package NetFox; C?T\5}h
@XV&^l-
'.(Gg%*\.
public class TestMethod { o1x1SH
"8{A4N1B5
}: HG)V
public TestMethod() .'gm2
{ ///xx/weblogic60b2_win.exe x9 %=d
try{ dQ.#8o=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %gh#gH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N}K [Q=
SiteFileFetch fileFetch = new SiteFileFetch(bean); IrqM_OjC
fileFetch.start(); oDz|%N2s|
} E)gD"^rex
catch(Exception e){e.printStackTrace ();} #e|o"R;/`
2 HEU
dD=$$( je
} a3tcLd|7J
89g a+#7
JfIXv
public static void main(String[] args) 4JAz{aw'b
{ v{VF>qEP
new TestMethod(); og5VB
} )hXTgUZa
} %+N]$Q
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