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)); ,s.{R
} Weu%&u-
for(int i=0;i<nEndPos.length-1;i++) %}x$YDO
{ =V(|3?N
nEndPos = nStartPos[i+1]; - BE.a<
} iZbY@-3fc
nEndPos[nEndPos.length-1] = nFileLength; ZclZD{%8J
} $`O%bsjX
} 0CFON2I
"FfIq;
Y,;$RV@g
//启动子线程 8M9}os
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x;L.j7lzA;
for(int i=0;i<nStartPos.length;i++) u#sbr8Y
{ NiPa-yRh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1e(QI) ~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !1<?ddH6
nStartPos,nEndPos,i); g Xi& S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P6 & _q
fileSplitterFetch.start(); Q@"mL
} E`aAPk_y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fy'/8Yv#L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XBF]|}%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z0Bw+&^]}
nEndPos = " + nFileLength); NL76 jF
// fileSplitterFetch[nPos.length-1].start(); {u4=*>?G
s)<^YASg
m\O|BMHn
//等待子线程结束 c2iPm9"eh
//int count = 0; C\WU<!
//是否结束while循环 ;DXcEzV
boolean breakWhile = false; IS9}@5`'
uv$t>_^
? pkg1F7
while(!bStop) c5f8pa *
{ M^twD*
write_nPos(); *6b$l.Vs
Utility.sleep(500); G*x"drP
breakWhile = true; 6;8Jy
z/&2Se:
Yo$NE
for(int i=0;i<nStartPos.length;i++) qh<h|C]V
{ _xVtB1@kLM
if(!fileSplitterFetch.bDownOver) 1s@%q <
{ Y::I_6[eV
breakWhile = false; 5\6S5JyIL
break; pf'-(W+
} ]l.qp5eQ
} t:?8I9d
if(breakWhile) gfW8s+
break; {Hp*BE
h;(#^+LH
M]JD(
//count++; zLB7'7oP
//if(count>4) X\dPQwasM
// siteStop(); 7Ne`F(c
} 8ezdU"
Rl2*oOVz
W@(EEMhw
System.err.println("文件下载结束！"); O%KP,q&}Y
} &&\HE7*
catch(Exception e){e.printStackTrace ();} O=Cz*j
} |re>YQ!zd
?z]hYsy
-(Y(K!n
//获得文件长度 %Gk?f=e
public long getFileSize() (g8<"< N?
{ =ZaTD-%id
int nFileLength = -1; ee0)%hc1t
try{ vg6'^5S7
URL url = new URL(siteInfoBean.getSSiteURL()); 3TDjWW;#~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @TTB$
httpConnection.setRequestProperty("User-Agent","NetFox"); }%;o#!<N(@
V&75n.L
j~)GZV
int responseCode=httpConnection.getResponseCode(); uR:@7n
if(responseCode>=400) @},25"x)
{ p[zKc2TPk
processErrorCode(responseCode); ?k*%r;e>
return -2; //-2 represent access is error 3~mi
} 9 Z5!3
!Xzne_V<
JQtBt2
String sHeader; tf5h/:
{M.OOEcIp
#J,?oe=<4
for(int i=1;;i++) N5SePA\ ,?
{ >5aZ?#TS1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wM"PJG
//Utility.log(in.readLine()); 2qF ?%
sHeader=httpConnection.getHeaderFieldKey(i); R2 I 7d'|v
if(sHeader!=null) <Xsy{7
{ {H5a.+-(bE
if(sHeader.equals("Content-Length")) ~_ 8X%uty
{ ])sIQ{P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l|z0aF;z
break; b,8\i|*!f
} `=zlS"dQ
} qkEre
else M!9gOAQP
break; U>,E]'
} ka^sOC+Y
} M'n2j
catch(IOException e){e.printStackTrace ();} 122%KS
catch(Exception e){e.printStackTrace ();} 8-2e4^ g(
yyj?hR@rZ
w4m)lQM
Utility.log(nFileLength); {7%W/C#A
DLWG0$#!
zv^km5by
return nFileLength; DhVF^=x$
} R@+%~"Z
gNsas:iGM
/mM#nS
//保存下载信息（文件指针位置） o<Esh;;*nm
private void write_nPos() -Dx_:k|k
{ \x,q(npHi
try{ {c;][>l
output = new DataOutputStream(new FileOutputStream(tmpFile)); r?w^#V
output.writeInt(nStartPos.length); N'8u}WO
for(int i=0;i<nStartPos.length;i++) E=-ed9({:
{ cQ?eL,z
// output.writeLong(nPos); tTMYqgzUk
output.writeLong(fileSplitterFetch.nStartPos); O)$rC
output.writeLong(fileSplitterFetch.nEndPos); N}j]S{j}'
} -8r';zR
output.close(); &7i o/d\/
} ~^{jfHTlv
catch(IOException e){e.printStackTrace ();} 5-3.7CO$
catch(Exception e){e.printStackTrace ();} gyz#:z$p^
} Q(3Na6
%a_ rYrL
w=ib@_:f
//读取保存的下载信息（文件指针位置） bK\Mn95]
private void read_nPos() |[RoR
{ YPV@/n[N
try{ Vw^2TRU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Tke3X\|
int nCount = input.readInt(); CWTPf1?eB
nStartPos = new long[nCount]; x'4q`xDa
nEndPos = new long[nCount]; .d JX,^
for(int i=0;i<nStartPos.length;i++) GV+K] KDI
{ kgq"b)
nStartPos = input.readLong(); y.O%
nEndPos = input.readLong(); m>H+noc^
} ?)_?YLi
input.close(); fbG+.'
} g[NmVY-o
catch(IOException e){e.printStackTrace ();} 8zMt&5jD
catch(Exception e){e.printStackTrace ();} ]f3[I3;K
} W7F1o[
$j+RUelFY
9?jD90@ }
private void processErrorCode(int nErrorCode) BrHw02G
{ V>$A\AWw
System.err.println("Error Code : " + nErrorCode); ?F^$4:
} }f~:>N#
+ Z7 L&BI
,[} XK9
//停止文件下载 R;G"LT
public void siteStop() 7z_EX8^
{ JJHfg)
bStop = true; _uYidtxo=
for(int i=0;i<nStartPos.length;i++) \4/zvlo]h
fileSplitterFetch.splitterStop(); OH(w3:;[8
prWK U
Q.]$t 2J
} lBpy0lo#
} '^npZa'%sW
//负责部分文件的抓取 U9*uXD1\
**FileSplitterFetch.java .~nk'm
*/ _5t~g_(1OK
package NetFox; +;T `uOF}
&}:]uC
;*H@E(g
import java.io.*; KWq&<X5
import java.net.*; @PaOQ@
T4M"s;::1
dHzQAqb8J
public class FileSplitterFetch extends Thread { Z7="on4
\Nvu[P
}MCh$
String sURL; //File URL D(' w<9.
long nStartPos; //File Snippet Start Position i40'U?eG~6
long nEndPos; //File Snippet End Position +nz6+{li\
int nThreadID; //Thread's ID 61[ 8I},V
boolean bDownOver = false; //Downing is over +.EP_2f9
boolean bStop = false; //Stop identical Az`c? W%
FileAccessI fileAccessI = null; //File Access interface UdiogXZ
M2$.Yom[
\~(scz$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mSg{0_:
{ }Ai_peO0a
this.sURL = sURL; T"b'T>Y
this.nStartPos = nStart; MMQ^&!H
this.nEndPos = nEnd; BidTrO
nThreadID = id; y^*o%2/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t1Zcr#b>
} @U 6jd4?)
+sW;p?K7eO
mw\ z'
public void run() :j)v=qul
{ v7h!'U[/
while(nStartPos < nEndPos && !bStop) `<"@&N^d
{ YUGEGXw
H,{WrWA
B%.vEk)*
try{ G[bWjw86O
URL url = new URL(sURL); }%T8?d]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v<_wf
httpConnection.setRequestProperty("User-Agent","NetFox"); &P0jRT3e#Y
String sProperty = "bytes="+nStartPos+"-"; v>[U*E
httpConnection.setRequestProperty("RANGE",sProperty); w YEkWB^
Utility.log(sProperty); &c|3v!
4X1!t
vOIzfwYG9
InputStream input = httpConnection.getInputStream(); -K@mjN
//logResponseHead(httpConnection); LwI A4$d
O-=~Bn _
C)a;zU;9
byte[] b = new byte[1024]; OpNxd]"T
int nRead; DO^J=e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GBvgVX<
{ ROWI.|
nStartPos += fileAccessI.write(b,0,nRead); UA8*8%v
//if(nThreadID == 1) B1U<m=Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sU=7)*$
} ZHN@&Gg6)
%3:[0o={d
J-k/#A4o
Utility.log("Thread " + nThreadID + " is over!"); K!+IRA@
bDownOver = true; Y6Mp[=
//nPos = fileAccessI.write (b,0,nRead); C9FzTg/c
} vT&) 5nN
catch(Exception e){e.printStackTrace ();} 4%GwCEnS
} 2LTMt?
} `q$a p$?
YaT6vSz
%*A|hK+G:W
//打印回应的头信息 JG:li} N
public void logResponseHead(HttpURLConnection con) 0^-1/Ec
{ okkMx"
for(int i=1;;i++) }<9IH%sgF
{ ] oMtqkiR
String header=con.getHeaderFieldKey(i); XH`W(
if(header!=null) zgnZ72%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z|k0${iu#
Utility.log(header+" : "+con.getHeaderField(header)); 6/=0RTd
else b)(rlX
break; d$gT,+|vu
} #GbfFoE
} }|j\QjH
_-R&A@
y[64O x
public void splitterStop() b;5&V_
{ h6(\ tRd!\
bStop = true; (rE.ft5$9
} ~85>.o2RDW
ea3f`z
2gM/".|{
} tYk!Y/O}
GpZ}xY'|w,
@4]} J-3
/* JGRL&MG4
**FileAccess.java unB`n'L
*//文件访问(定位，写) 579<[[6~d2
package NetFox; '~\\:37+
import java.io.*; &*YFK/]
2e<u/M21>
4c'F.0^
public class FileAccessI implements Serializable{ i!i=6m.q7
EZee kxs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WZQ EBXs
RandomAccessFile oSavedFile; 6g-Q
long nPos; >At* jg48
@d1YN]ede
3Jh!YzI8
public FileAccessI() throws IOException l8~s#:v6X
{ %Ek!3t
this("",0); Ef]<0Tm]:
} 6.'j\
dQQ!QbI(.
RA$%3L[A!
public FileAccessI(String sName,long nPos) throws IOException ) -^(Su(!
{ @j`gxM_-O
oSavedFile = new RandomAccessFile(sName,"rw"); ?e#bq]
this.nPos = nPos; xiy=D5N.=
oSavedFile.seek(nPos); &~KAZ}xu
} Z4s+8cTHn
WXs?2S*
R^?9V=Y<T
public synchronized int write(byte[] b,int nStart,int nLen) hCPyCq]
{ #;])/8R%
int n = -1; >n"4M~I
try{ H{et2J<H
oSavedFile.write(b,nStart,nLen); B(1WI_}~
n = nLen; cfC}"As
} V)Sw\tS6g
catch(IOException e) 7SJbrOL4Q-
{ ;u*I#)7
e.printStackTrace (); %:!ILN
} <;lwvO
ey@{Ng#
TFG0~"4Cz
return n; 7tP qez#
} qORL 7?{
Lyq[gQjr
&[7z:`+Y##
} AaLbJYuKd
rcAPp
;Xl {m`E+
/* FI"KJk'
**SiteInfoBean.java +.-g`Vyz*
*/ cb5T-'hY
package NetFox; y!VL`xV
PS3jCT
2-pv &
public class SiteInfoBean { 2(2UAB"u
TZ#^AV=ae
EYRg,U&'
private String sSiteURL; //Site's URL q|sT4} =
private String sFilePath; //Saved File's Path T"/dn%21
private String sFileName; //Saved File's Name ] B?NDxU
private int nSplitter; //Count of Splited Downloading File v|R#[vtFd
8bdx$,$k
64qqJmG3
public SiteInfoBean() q&2L@l3A
{//nSplitter的缺省值为5 hplxs#
//default value of nSplitter is 5 sQmJ3 (:HO
this("","","",5); sLd%m+*p
} vcC"
69S*\'L
0[f[6mm%m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :?j]W2+kR
{ Jb6)U]
sSiteURL= sURL; wv
sFilePath = sPath; 1T}jK^"
sFileName = sName; NpH9},1i
this.nSplitter = nSpiltter; 2 b80b50
%)w7t[A2D
AAF']z<4_"
} *RmD%[f
=wMq!mBd
Z#%s/TL
public String getSSiteURL() +`7!4gxwK!
{ E>N[
return sSiteURL; >mj WC) U
} d*dPi^JjC
7l4}b^>/`
^"iJ
public void setSSiteURL(String value) cs 58: G5
{ K+|0~/0
sSiteURL = value; (QS 0
} {s0!hp
a1shP};pK
OkMAqS
public String getSFilePath() Gi\Z"MiBZ
{ SB`xr!~A]
return sFilePath; 2O}X-/H
} 0j2mTF(C
Te`MIR
NNMn,J
public void setSFilePath(String value) LRR)T: e}q
{ kP1cwmZ7F
sFilePath = value; a4mRu|x
} |-TxX:O-
|S]T,`7u
IdCE<Oj\
public String getSFileName() R[l~E![!j
{ `neo.]
return sFileName; 4|UtE<<b
} &\ K
}L @~!=q*
Oq:$GME
public void setSFileName(String value) h0C>z2iH
{ d.Q<!Au3
sFileName = value; U ]7;K>.T
} %'/^[j#
+F~B"a
:kC*<f\
public int getNSplitter() !+DhH2;)F
{ 4n*`%V
return nSplitter; U|b)Bw<P
} ZAgtVbO7
>`<qa!9
o7^0Lo5Z?
public void setNSplitter(int nCount) .LGA0
{ xyHv7u%*
nSplitter = nCount; z'*{V\
} \wR\i^
} bc;?O`I<
o*3\xg
kG5Uc83#G
/* 3_>=Cv}
**Utility.java CSH*^nk':O
*/ !b$]D?=}
package NetFox; I|Mw*2U
-;Te+E_
)x35
public class Utility { u $B24Cy.
^O}J',Fm%f
qC3PKlhv6
public Utility() 1k`gr&S
{ eIOMW9Ivt
2cwJ);Eg2
xIH= gK
} mC3:P5/c
gGx<k3W^
//线程睡眠 ND/oKM+?
public static void sleep(int nSecond) h gu\~}kD
{ wYDdy gS
try{ Lt i2KY}/%
Thread.sleep(nSecond); {Es1bO
} >U(E \`9D
catch(Exception e) !%B-y9\
{ oi8M6l
e.printStackTrace (); ge1U1o
} (hh^?
} AmQsay#I_
P<;Puww/
//日志 EKS?3z%!
public static void log(String sMsg) iBmvy7S?
{ 8"A0@fNz
System.err.println(sMsg); +11oVW
} KUC%Da3
"rVM23@ tq
Asy2jw\V
public static void log(int sMsg) D={$l'y9p
{ ],vid1E
System.err.println(sMsg); QU(Lv(/O
} b`ksTO`}x
} HBs 6:[q
`R!2N4|;
FEX67A8/;
/* ;9q$eK%d
**TestMethod.java W@i|=xS?
*/ MO|Pv j~[
package NetFox; ,@I\'os
J(A+mYr{:
KFy|,@NI
public class TestMethod { PZ#aq~>w
>U?#'e{qW
L0w2qF
public TestMethod() 4G hg~0
{ ///xx/weblogic60b2_win.exe L">m2/ HG
try{ er2;1TW3E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P@x@5uC2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ggpa!R
SiteFileFetch fileFetch = new SiteFileFetch(bean); B*P;*re
fileFetch.start(); #WGyQu
} s.XxYXR\
catch(Exception e){e.printStackTrace ();} 6j!a*u:}"
7[i&EPN
"{3MXAFe
} /<dl"PWkJv
%e_){28 n
M'oQ<,yW-
public static void main(String[] args) db}lN
{ Bo1 t}#7
new TestMethod(); *Wcq'S
} 9>ZX@1]m_
} `6LVXDR
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