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)); PeLzZ'$D
} Gq%,'amf
for(int i=0;i<nEndPos.length-1;i++) N0ef5J JM`
{ FJ{&R Ld
nEndPos = nStartPos[i+1]; hx4c`fOs
} I SdB5Va
nEndPos[nEndPos.length-1] = nFileLength; Im]6-#(9\|
} @~&^1%37)
} EN8xn9M?
D^U?!S&4~
fhC|=0XB
//启动子线程 >McEuoZx9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5dbj{r)s6i
for(int i=0;i<nStartPos.length;i++) ov >5+"q)
{ K(P.i^k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w02C1oGfx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^oClf(
nStartPos,nEndPos,i); @Q&k6.{4Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H7meI9L
fileSplitterFetch.start(); a6;5mx
} &^Gp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C<w&mFozL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cJM.Q_I}Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,e GF~
nEndPos = " + nFileLength); .*J /F$
// fileSplitterFetch[nPos.length-1].start(); PR,8c
VtGZB3
%u2",eHCB
//等待子线程结束 4[Wwm
//int count = 0; $H&:R&Us
//是否结束while循环 eF' l_*
boolean breakWhile = false; gyT0h?xDt
;Sp/N4+
Z.s0ddMs
while(!bStop) (CJx Y(1K
{ A5_r(Z-5
write_nPos(); o*oFCR]j
Utility.sleep(500); .kgt?r
breakWhile = true; 9w=[}<E
k]2_vk^
MN:LL <
for(int i=0;i<nStartPos.length;i++) E Q:6R|L
{ |=V~CQ]
if(!fileSplitterFetch.bDownOver) rD9:4W`^
{ |.-Muv
breakWhile = false; vskp1Wi(
break; 8`90a\t'Z
} zw iS%-F
} <|w(Sn
if(breakWhile) q0NToVo@
break; *9EW&Ek
"98j-L=F+
x+DecO2
//count++; cIrc@
//if(count>4) k~fH:X~x
// siteStop(); kdhwnO
} |t~>Xs
wti
>5D;uTy u
System.err.println("文件下载结束！"); 2(Aw
} GR_caP
catch(Exception e){e.printStackTrace ();} n9-WZsc1
} vF/wV'Kk
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$R:Q R?
//获得文件长度 vUDMl Z
public long getFileSize() S6fbwZZMG
{ o7eWL/1
int nFileLength = -1; D'BGoVP
try{ 6& 6|R3
URL url = new URL(siteInfoBean.getSSiteURL()); o^r\7g6\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v2="j
httpConnection.setRequestProperty("User-Agent","NetFox"); )t CNp
g${k8.TV
{i}E)Np
int responseCode=httpConnection.getResponseCode(); k+Z2)j"
if(responseCode>=400) [khXAf1{Q
{ zJ@^Bw;A^@
processErrorCode(responseCode); ntW1 )H'o
return -2; //-2 represent access is error S,Tc\}
} QZ*gR#K]Sz
[ugr<[6
MV07RjeS
String sHeader; -=ZDfM
q;7DH4;t
k|U2Mp
for(int i=1;;i++) H6U5-
{ DKkilqVM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OB*V4Yv
//Utility.log(in.readLine()); {<?8Y
sHeader=httpConnection.getHeaderFieldKey(i); $dA]GWW5A
if(sHeader!=null) ]b:>7_la
{ 9Hd_sNUu\
if(sHeader.equals("Content-Length")) ExeZj8U
{ E=`/}2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c5:X$k\
break; 9PMIF9"
} |--Jd$ dj
} ''3I0X*!
else q%dbx:y#
break; ?-)v{4{s
} [1O{yPV3s
} X; 6=WqJj
catch(IOException e){e.printStackTrace ();} ,i8%qm8
catch(Exception e){e.printStackTrace ();} ;~'&m
vhcp[=e :
6Rmdf>a
Utility.log(nFileLength); Rz[3cN)?q
(NN;1{DB8
RgZ9ZrE\
return nFileLength; S5d
} \f)GW$`
%$i}[U
W+$G{XSr5C
//保存下载信息（文件指针位置） ?Dn}
private void write_nPos() l@ (:Q!Sk
{ TwI'XMO;A
try{ qI${7
output = new DataOutputStream(new FileOutputStream(tmpFile)); g4952u
output.writeInt(nStartPos.length); j-.Y!$a%6
for(int i=0;i<nStartPos.length;i++) 5pK _-:?
{ +T8MQ[(4
// output.writeLong(nPos); 8@RtL,[d
output.writeLong(fileSplitterFetch.nStartPos); (.VS&Kv#U
output.writeLong(fileSplitterFetch.nEndPos); S4'<kF0z
} *[|+5LVn
output.close(); }W&9}9p"
} {8oGWQgrj
catch(IOException e){e.printStackTrace ();} +C[g>c}d
catch(Exception e){e.printStackTrace ();} 1ANb=X|hig
} b6p'%;Y/
$2RSYI`py
lW|v_oP9
//读取保存的下载信息（文件指针位置） Aa4Tq2G
private void read_nPos() ,>8w|951'
{ )^+hm+27v
try{ e<[ ] W4"A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;_2+Y^Qb
int nCount = input.readInt(); N_Kdi%q
nStartPos = new long[nCount]; Vzo<ma^
nEndPos = new long[nCount]; ;BYuNQr
for(int i=0;i<nStartPos.length;i++) ra>2<
{ -esQyLx
nStartPos = input.readLong(); -6~.;M 5
nEndPos = input.readLong(); P;mp)1C
} =0!j"z=
input.close(); RZ;s_16GQ
} V; CPn
catch(IOException e){e.printStackTrace ();} S!+>{JyQ
catch(Exception e){e.printStackTrace ();} y@It#!u0
} 7nFOVZ
/ *PHX@
bLAHVi<.
private void processErrorCode(int nErrorCode) 'tvuw\hhL
{ ,?k1if(0[
System.err.println("Error Code : " + nErrorCode); ,v,rY'
} _53~D=
mt`CQz"_
RHMXPsj
//停止文件下载 RjVmHhX
public void siteStop() |_>^vW1f
{ q=V'pML
bStop = true; x!\q69ndv
for(int i=0;i<nStartPos.length;i++) ~BX=n9
fileSplitterFetch.splitterStop(); [/%N2mj
e}S+1G6r)
75lh07
} ^gZ,A]
} d7 H*F
//负责部分文件的抓取 TlRc8r|
**FileSplitterFetch.java ^|]Dg &N.
*/ ~x#TfeU]
package NetFox; x3Y)l1gh
b*M?\ aA
nP]!{J]
import java.io.*; q$mc{F($D
import java.net.*; ]z/R?SM
"\KBF
G3%Ju=
public class FileSplitterFetch extends Thread { =I)43ahd
~~ rR< re
!hhL",
String sURL; //File URL j)6p>6
long nStartPos; //File Snippet Start Position yxo=eSOM
long nEndPos; //File Snippet End Position m<#12#D
int nThreadID; //Thread's ID 5<R m{
boolean bDownOver = false; //Downing is over ;%B9mM#p~
boolean bStop = false; //Stop identical V?1 $H
FileAccessI fileAccessI = null; //File Access interface 1/2cb-V
Z>Mv$F"p:
cgSN:$p(R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <7`zc7c]#
{ <.B+&3')
this.sURL = sURL; $[n:IDa*@1
this.nStartPos = nStart; }$4z$&
this.nEndPos = nEnd; >[,eK=
nThreadID = id; ?'9IgT[*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~~Ezt*lH
} yi>AogQ,
. yg#
f$ xp74hw3
public void run() d6YXITL)\>
{ U/QgO
while(nStartPos < nEndPos && !bStop) |#kY_d)10
{ m(6d3P
a[(OeVQ5
qul#)HI
try{ dkZe.pv$j
URL url = new URL(sURL); ;54NQB3L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pUb1#=
httpConnection.setRequestProperty("User-Agent","NetFox"); g-~ _gt7
String sProperty = "bytes="+nStartPos+"-"; (^m] 7l
httpConnection.setRequestProperty("RANGE",sProperty); 0f.jW O
Utility.log(sProperty); <ak[`]
2 HEU
dD=$$( je
InputStream input = httpConnection.getInputStream(); ?<TJ}("/
//logResponseHead(httpConnection); 49$<:{~
7upko9d/
h@!p:]
byte[] b = new byte[1024]; hx$61E=
int nRead; 7GYf#} N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :^v Q4/,
{ C,Nf|L((6
nStartPos += fileAccessI.write(b,0,nRead); %+N]$Q
//if(nThreadID == 1) Pc`d]*BYi
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )Y7H@e\1
} VAz4@r7hkq
ApXf<MAy
'z(Y9%+a
Utility.log("Thread " + nThreadID + " is over!"); Pwl*5/l
bDownOver = true; '|[V}K5m/f
//nPos = fileAccessI.write (b,0,nRead); q"u,Tnc;
} A iM ukd,
catch(Exception e){e.printStackTrace ();} yx :^*/
} fY[Fwjj3
} 1^![8>u"
"w'pIUQ3,
HcsVq+
//打印回应的头信息 j|k/&q[St
public void logResponseHead(HttpURLConnection con) s)a-ky(
{ 6]?mjG6
for(int i=1;;i++) 3' i6<
{ E1eGZ&&Gd
String header=con.getHeaderFieldKey(i); CO='[1"_5
if(header!=null) EfrQ~`\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ayy\7b
Utility.log(header+" : "+con.getHeaderField(header)); ?e$&=FC0;
else g X!>ef
break; x#D%3v"l_*
} p"ZvA^d\
} K381B5_h
-e/}DGL
!C#oZU]P
public void splitterStop() f+cb83}n]
{ QxYm3x5
bStop = true; |Vx[
} +'<PW+U$
.gx^L=O:
da7"Q{f+
} mqZH<.mn
hCcI]#S&
/iU<\+ H
/* TTz=*t+D
**FileAccess.java ]y_:+SHc
*//文件访问(定位，写) @7twe;07r
package NetFox; -tj#BEC[H(
import java.io.*; k$3pmy*
JU?;Kq9R
!9;m~T7.
public class FileAccessI implements Serializable{ ba|xf@=&
,8@<sFB'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d`^3fr'.4A
RandomAccessFile oSavedFile; o08WC'bX
long nPos; |g&V? lI
Lv%3 jj
8;@y\0
public FileAccessI() throws IOException >n"0>[:4
{ NnLK!Q
this("",0); [ohLG_9
} FS1\`#Bm)
r%U6,7d=)
{r_HcI(h
public FileAccessI(String sName,long nPos) throws IOException rmX*s}B
{ Hd~g\
oSavedFile = new RandomAccessFile(sName,"rw"); /mkT7,]
this.nPos = nPos; a{kJ`fK
oSavedFile.seek(nPos); wpK1nA+7N
} ,1sbY!&ekL
?^Rp" H
e )0 ]WJ
public synchronized int write(byte[] b,int nStart,int nLen) & FhJ%JK
{ t1w5U+z
int n = -1; zZCl]cql
try{ q\EYsN</;
oSavedFile.write(b,nStart,nLen); Cn~VJ,l g
n = nLen; 4 Ej->T.
} TKB8%/_p
catch(IOException e) n _K1%
{ d{S'6*`D
e.printStackTrace (); c4fH/-
} YV.' L
*yhA8fJ
Z@zo~*o
return n; v"k ?e
} ^*ZaqMA
xX<f4H\'
"\o#YC
} w6vbYPCN
KuJ)alD;1
}4C_r'd6
/* 1-y8Hy_a2
**SiteInfoBean.java <=.6Z*x+
*/ <2pp6je\0s
package NetFox; 6Z_V,LD9L
a|t~&\@
/a1uG]Mt
public class SiteInfoBean { w%])
RTmp$lV
NXOXN]=c<
private String sSiteURL; //Site's URL %~Yo{4mHs
private String sFilePath; //Saved File's Path ;Nn(
private String sFileName; //Saved File's Name v9f+ {Y%-
private int nSplitter; //Count of Splited Downloading File jEBn"]\D
oMbd1uus
:s *
public SiteInfoBean() |5~Oh`w
{//nSplitter的缺省值为5 ~J].~^[
//default value of nSplitter is 5 #*iUZo
this("","","",5); ~0PzRS^o
} >$m<R&
VIF43/>(
U"GxXrl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p<L7qwOii
{ B?j t?
sSiteURL= sURL; /|v4]t-
sFilePath = sPath; ]9YA~n\
sFileName = sName; u> {aF{
this.nSplitter = nSpiltter; 'yiv.<4
D6VdgU|
SJiQg-+<Uf
} rj=as>6B
edL2ax
Ze0qRLuH!
public String getSSiteURL() v2x+_K}J
{ }b1G21Dc!
return sSiteURL; !>9s
} pT,8E(*l2
9nAP%MA`
NJBSVCb
public void setSSiteURL(String value) irlFB#..
{ n-9xfn0U~#
sSiteURL = value; XM\\Imw
} Vlx.C~WYn
}TTghE!
6_`Bo%
public String getSFilePath() f/Y&)#g>k
{ zmhc\M?z
return sFilePath; &{j!!LL
} ?M:>2wl
eA& #33
9^/Y7Wp/@
public void setSFilePath(String value) `KZV@t
{ N:lE{IvRJ
sFilePath = value; ,V1"Typ#<
} _<AkM"
b+~_/;Y9
6Q:Wo)^!
public String getSFileName() q(n"r0)=
{ `NtW+v
return sFileName; vEI{AmogRx
} c0o]O[
.=eEuH
zQ+Mu^|u+
public void setSFileName(String value) $NR[U+
{ /l<(i+0
sFileName = value; HO<|EH~lu
} |Ahf 01
;a?<7LIx
6/<Hx@r (
public int getNSplitter() k^cZePqE6d
{ L-(bw3Yr>
return nSplitter; gY7sf1\wX
} EK# 11@0%
Phi5;U!
QD7KE6KP'
public void setNSplitter(int nCount) =DdPwr 0Op
{ Rrh6-]A
nSplitter = nCount; 4bk`i*-O
} "s|P,*Xf
} K+)3 LR^
6,5h4[eF*
o}Grb/LJ
/* 8y27O
**Utility.java 'xta/@Sq
*/ aV$kxzEc
package NetFox; brmSJ7
t"B3?<?]
8-@@QZ\N
public class Utility { YC1Bgz
\Vme\Ke*v)
+q pW"0[
public Utility() ymm]+v5S.]
{ dU9;sx
_&]7
6rnFXZ\
} Md4Q.8
GTLS0l)
//线程睡眠 '1D$ ;
public static void sleep(int nSecond) 1 3]e< '
{ *IOrv)
try{ |?V7E\S
Thread.sleep(nSecond); W(]A^C=/
} LM eI[Ji
catch(Exception e) ^mLX}E]
{ rCF=m]1zxT
e.printStackTrace (); g)6>=Qo`8E
} (2eS:1+'8
} Z7bJ<TpZ
?wHhBh-Q
//日志 85!]NF
public static void log(String sMsg) 7RDmvWd-'?
{ H{n:R *
System.err.println(sMsg); CzG[S\{+
} jOT/|k
Stwg[K0<
R[zN?
public static void log(int sMsg) ueJ^Q,-t
{ Ug+ K:YUq
System.err.println(sMsg); cD]H~D}M
} DY#195H
} w4P;Z-Cd
I8! .n
GZi`jp
/* ?lkB{-%rQ
**TestMethod.java @2T8H
*/ }vh <x6
package NetFox; _FOIMjh%N
d:hnb)I$*
.#~!w!T
public class TestMethod { 8XYxyOl
"*HM8\
:|9vMM^$
public TestMethod() 2->Lz
{ ///xx/weblogic60b2_win.exe SZTn=\
try{ p0W<K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]A}ZaXd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '4M{Xn}@
SiteFileFetch fileFetch = new SiteFileFetch(bean); m!KEK\5M?
fileFetch.start(); Je|:\Qk
} 1qR$ Yr\
catch(Exception e){e.printStackTrace ();} v)np.j0V7
E G+/2o+W
&OJ?Za@p@)
} hY!ek;/Gc
6~sU[thGW
M@KQOAzt
public static void main(String[] args) l@&-be
{ 0S:&wb
new TestMethod(); ,y'6vW`%g9
} YCE *Dm
} $VQ;y|K+[
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