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)); CflGj0oy8
} RO]Vn]qb
for(int i=0;i<nEndPos.length-1;i++) _aR_[
{ [|XMR=\>
nEndPos = nStartPos[i+1]; "wB~*,Ny
} }AZ0BI,TI
nEndPos[nEndPos.length-1] = nFileLength; D]{#!w(d
} ;~2RWj=-
} rhLm2q
d^0vaX6e}
g.&n X/
//启动子线程 ?D6?W6@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xcF:moL
for(int i=0;i<nStartPos.length;i++) .??[qBOTE
{ 0E6tH& ;>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #LGAvFA*_F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dK5|tWJX
nStartPos,nEndPos,i); fG+/p 0sJ?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ':}
fileSplitterFetch.start(); jO|D#nC
} wVSk.OOB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |6M:JI8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HI` q!LPv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yBd#*3K1
nEndPos = " + nFileLength); CSUXa8u7
// fileSplitterFetch[nPos.length-1].start(); ?"d25LyN
IfK%i/J
u~WE}VC
//等待子线程结束 G,VTFM6
//int count = 0; O%1X[
//是否结束while循环 MDHTZ94\Q
boolean breakWhile = false; r+4<Lon~
o@&Hc bN^
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while(!bStop) D4@'C4kL
{ |>/T*zk<
write_nPos(); ^7qqO%
Utility.sleep(500); 9^DXw!
breakWhile = true; zlUXp0W
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for(int i=0;i<nStartPos.length;i++) "sM 3NY
{ E{Tvjh+
if(!fileSplitterFetch.bDownOver) Rxg^vM*
{ zA~aiX
breakWhile = false; t_VF=B^LuR
break; p\"WX
} \Ax[/J2aO
} s.9)?<[
if(breakWhile) ODggGB`H`
break; 8Pkw'.r
^}F@*A;o
4axc05
//count++; }JF,:g Lk
//if(count>4) w7(jSPB
// siteStop(); #>]o'KQx
} jm~qD T,
/2<1/[#
U2lDTRt
System.err.println("文件下载结束！"); {JJq/[j
} F$|Ec9
catch(Exception e){e.printStackTrace ();} 5kRP Sfh
} -W#-m'Lvu
X-Yy1"6m1
`egyk)"aM
//获得文件长度 |uT&M`7\{
public long getFileSize() /]_a\x5Ss
{ (_9cL,v
int nFileLength = -1; PB W.nm
try{ !oJ226>WI
URL url = new URL(siteInfoBean.getSSiteURL()); 3;N+5*-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kVH^(Pi
httpConnection.setRequestProperty("User-Agent","NetFox"); 6v]y\+
5D~>Ed;
53i7:1[uV
int responseCode=httpConnection.getResponseCode(); 5ree3 quh
if(responseCode>=400) Q#,j,h
{ voD0u
processErrorCode(responseCode); U&(TqRi,
return -2; //-2 represent access is error SEL7,8 Hm
} GC<zL}
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DKvNQ:fI>9
String sHeader; 2E*k@
b{Qg$ZJeR
.3tyNjsn\
for(int i=1;;i++) x+X^K_*
{ jOE~?{8m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E&RiEhuv
//Utility.log(in.readLine()); bR0z$~
sHeader=httpConnection.getHeaderFieldKey(i); Zl:Z31
if(sHeader!=null) w`77E=
{ ?)60JWOJ1
if(sHeader.equals("Content-Length")) RH"&B`
{ t!u{sr{j=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FTA[O.tiG
break; gmU0/z3&
} Yw\7`
} k *#fN(_
else Wl4T}j
break; {|jrYU.k~
} PN +<C7/
} MmvMuX]#)
catch(IOException e){e.printStackTrace ();} gLH#UwfJ
catch(Exception e){e.printStackTrace ();} 6?CBa]QG
]rhxB4*1
M[Kk43;QY!
Utility.log(nFileLength); )Q!3p={S*
v)TFpV6b{p
Wb|xEwqd`
return nFileLength; M< T[%)v
} x;G~c5
N@z+h
}`SXUM_sD`
//保存下载信息（文件指针位置） IO(Y_7
private void write_nPos() #4iiY6
{ e/h2E dY
try{ yD0,q%B`}
output = new DataOutputStream(new FileOutputStream(tmpFile)); WC?}a^ 8
output.writeInt(nStartPos.length); Ke_&dgsq
for(int i=0;i<nStartPos.length;i++) 1VH$l(7IQ
{ d+6 by,'
// output.writeLong(nPos); @_O,0d g
output.writeLong(fileSplitterFetch.nStartPos); 1o;*`
output.writeLong(fileSplitterFetch.nEndPos); xEA%UFB.!G
} +>F #{b
output.close(); (IrX\Y
} $p} /&
catch(IOException e){e.printStackTrace ();} E2PMcT{)_
catch(Exception e){e.printStackTrace ();} xyoh B#'W
} SSS)bv8m
CkJU5D
7=o2$
//读取保存的下载信息（文件指针位置） mNvK|bTUT
private void read_nPos() N'#Lb0`B
{ m-~eCFc
try{ qlUw;{;p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X@ljZ
int nCount = input.readInt(); Qe~2'Hw#9
nStartPos = new long[nCount]; 4-?'gN_
nEndPos = new long[nCount]; a-`OE"
for(int i=0;i<nStartPos.length;i++) @;-6qZ
{ #&@qmps(T
nStartPos = input.readLong(); #$vef
nEndPos = input.readLong(); +3c!.] o;
} ~)S Q{eK?&
input.close(); NMSpi[dr
} >};6>)0
catch(IOException e){e.printStackTrace ();} ]g>@r.Nc
catch(Exception e){e.printStackTrace ();} $Qm-p?f
} 3wS{@'
X9:(}=E V
)$#r6fQO
private void processErrorCode(int nErrorCode) !n=@(bT*wT
{ 0I.9m[<Fc
System.err.println("Error Code : " + nErrorCode); A2`QlhZ
} S=Ihg
n0X_m@
>.D0McQg
//停止文件下载 cx]O#b6B.
public void siteStop() BO5gwvyI
{ XFeeNcqF
bStop = true; 728}K^7:
for(int i=0;i<nStartPos.length;i++) !;SpQ28
fileSplitterFetch.splitterStop(); u_aln[oIv
\ B~9Ue!
/`iBv8!
} /H)K_H#|;
} tQ7DdVdix
//负责部分文件的抓取 :!a9|Fh~
**FileSplitterFetch.java Nxu10
*/ mm3goIi;Y
package NetFox; K_V44f1f
PmtBu`OkV
(89NK]2x
import java.io.*; @<]xbWhuw
import java.net.*; U*ZP>Vv
ZQvpkO7}M
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public class FileSplitterFetch extends Thread { z8bDBoD6
_nR8L`l*z
a;Ic!:L
String sURL; //File URL Kp*nOZ
long nStartPos; //File Snippet Start Position 9.|+KIRb
long nEndPos; //File Snippet End Position P'#m1ntxQ
int nThreadID; //Thread's ID lz!F{mR
boolean bDownOver = false; //Downing is over }DTpl?l
boolean bStop = false; //Stop identical iTU8WWY<
FileAccessI fileAccessI = null; //File Access interface t"`LJE._P
$Yt29AQ
8T'=lTJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O6P0Am7s
{ y D.S"
this.sURL = sURL; J/j1Yf'9
this.nStartPos = nStart; wTFM:N
this.nEndPos = nEnd; p.q:vI$J
nThreadID = id; b=a&!r5M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w:Fi 2aJ
} rE"`q1b#
@v9PI/c
;YxQo o>
public void run() U">D_ 8
{ TH2D;uv
while(nStartPos < nEndPos && !bStop) ;$@7iL
{ ]Ff"o7gT
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GZ\;M6{oh
try{ PIo/|1
URL url = new URL(sURL); buGW+TrWY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .-+_>br~
httpConnection.setRequestProperty("User-Agent","NetFox"); 5O&6 (Gaf
String sProperty = "bytes="+nStartPos+"-"; a +Q9kh
httpConnection.setRequestProperty("RANGE",sProperty); ;Jt*s
Utility.log(sProperty); U9IP`)z_5t
Vb06z3"r
I#Ay)+D
InputStream input = httpConnection.getInputStream(); gd[jYej'RP
//logResponseHead(httpConnection); 6\)61o_1|
EA%(+tJ^0
/Dj6Bj }
byte[] b = new byte[1024]; ,+P!R0PNH
int nRead; >`p`^:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) } ab@Nd$
{ bL (g$Yi
nStartPos += fileAccessI.write(b,0,nRead); m/n_e g
//if(nThreadID == 1) l2>G +t(,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T%K(opISc(
} Mjq1qEi"B
UiA\J
A] pLq`
Utility.log("Thread " + nThreadID + " is over!"); xh[Mmq/R
bDownOver = true; vrdlI^
//nPos = fileAccessI.write (b,0,nRead); ./mh9ax
} Ol:&cX3G
catch(Exception e){e.printStackTrace ();} EtJyI&7VK
} Ae:(_UJz
} (E59)z -
OwV>`BIwns
?8. $A2(Xw
//打印回应的头信息 7+JQaYO`"
public void logResponseHead(HttpURLConnection con) tYiK#N7
{ fM?HZKo
for(int i=1;;i++) Bv \ihUg/
{ I\PhgFt@O
String header=con.getHeaderFieldKey(i); uQWJ7Xm
if(header!=null) Qn(e[ C6\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W$ #FM$U
Utility.log(header+" : "+con.getHeaderField(header)); ?1i>b->
else #9}E@GGs
break; Z; Xg5
} <~t38|Ff@
} qI\qpWS\
\v{tK;
EcrM`E#kaZ
public void splitterStop() rA&|!1q"B
{ {MU>5\
bStop = true; 5Tluxt71
} LEvdPG$)
AZt~ \qf
T j9;".
} JLm0[1Lzd
lBh|+KN
vE7L> 7
/* _aL:XKM
**FileAccess.java XWZ *{/u
*//文件访问(定位，写) bEP-I5j1t
package NetFox; @FIR9XJ
import java.io.*; lb5Y$ZC
CUfD[un2D
q3JoU/Sf
public class FileAccessI implements Serializable{ N_Cu%HP
g #u1.|s&p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "12.Bi.O"[
RandomAccessFile oSavedFile; UOSa`TZbZ
long nPos; A>(m}P
RxU6.5N
z"bgtlfb8
public FileAccessI() throws IOException %50}oD@
{ hL~@Ah5&t
this("",0); %YG ~ql
} %@3AA<
JVf8KHDj
P;bl+a'gu
public FileAccessI(String sName,long nPos) throws IOException ZXljCiNn+\
{ g*F?
oSavedFile = new RandomAccessFile(sName,"rw"); i%+cPQ^o
this.nPos = nPos; C%t~?jEK~^
oSavedFile.seek(nPos); $r*7)/
} [?iA`#^d
p;`jmF
dX{|-;6vm
public synchronized int write(byte[] b,int nStart,int nLen) 4]A2Jl E
{ c-3AzB#[
int n = -1; 7)!(0.&
try{ =:n>yZ3T
oSavedFile.write(b,nStart,nLen); ]N_(M
n = nLen; $cEl6(66iX
} &$tBD@7
catch(IOException e) rlk0t159
{ no`c[XY
e.printStackTrace (); ty[bIaQi
} ?r0#{x~
-;&aU;k
$D +6=m[
return n; 34k<7X`I
} 8M*[RlUJB
]+;1)
0ohpJh61Q
} )$Xd#bzD|
A9\m.3jo
j9n3
/* ,S E5W2a]
**SiteInfoBean.java ]\w0u7}
*/ "- S2${
package NetFox; |F[E h ~
#XR<}OYcL
GY,l&.&
public class SiteInfoBean { ]J+}WR
YMOy6C
#-dfG.*
private String sSiteURL; //Site's URL JUXIE y^
private String sFilePath; //Saved File's Path pXf@Y}mH
private String sFileName; //Saved File's Name uN20sD}
private int nSplitter; //Count of Splited Downloading File W#87T_7T[
U.is:&]E
y}*rRm.:
public SiteInfoBean() 2.CjjI
{//nSplitter的缺省值为5 Ex9%i9H
//default value of nSplitter is 5 sE@t$'=
this("","","",5); Xd/gvg{??0
} \GS]jhEtn
(G $nN*rlu
aKXaor@0f.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Nq6~6Rr
{ A]"$O&l
sSiteURL= sURL; opxVxjTT#
sFilePath = sPath; S%gb1's
sFileName = sName; RpPbjz~
this.nSplitter = nSpiltter; .| CcUmx
BTjfzfO"
8"/5Lh(
} }ozlED`E
;> **+ezF
6wC|/J^
public String getSSiteURL() u}Vc2a,WV
{ s8Kf$E^?e.
return sSiteURL; 'b#RfF,7H}
} yE[ -@3v
XlIRedZ{
^_ <jg0V
public void setSSiteURL(String value) #mwV66'H
{ `RDlk
sSiteURL = value; CAyV#7[0
} EM]~yn!+
S'M=P_-7
!c-Ie~GIT
public String getSFilePath() D|m6gP;P
{ hV|pH)Nu{
return sFilePath; WqP>cl2Lm
} Y)^qF)v,d
RNGTSz
WGjT06a\
public void setSFilePath(String value) l<5O\?Vo]
{ %Z~,F?
sFilePath = value; tz0@csXV
} hgMh]4wN*
"]J4BZD
^]c/hb|X
public String getSFileName() Fgq"d7`9@
{ 3|zqEGT*
return sFileName; Su`LBz"
} U">J$M@
a7'.*H]
` W$
public void setSFileName(String value) $O"S*)9
{ ModwJ w
sFileName = value; c#sPM!!
} z3+y|nx!
AY4ZU CqI
WmU4~.
public int getNSplitter() pFi.?|6"
{ /.<%y8v
return nSplitter; ,ButNBv
} `$oGgz6ZT
'7G'R
<,p|3p3
public void setNSplitter(int nCount) *O-1zIlp
{ bOjvrg;Sz\
nSplitter = nCount; Poy ]5:.
} fP>_P#gZ
} 0VC8'6S_k
owL>w
ry9%Y3
/* ~qQSt%
**Utility.java 58\rl G
*/ v#*9rNEj0
package NetFox; WNSf$D{p
ETvn$ Jdp
%,f|H :+>u
public class Utility { RM\it"g
"jBrPCB 8
'qcLK>E
public Utility() nEu,1
{ h|OqM:J;
-1).'aJ^
K3*8JF7_F
} 0<*R 0
O{Bll;C
//线程睡眠 yf`Nh
public static void sleep(int nSecond) 0[ MQp"z
{ ({ 'I;]AQ
try{ i5wXT
Thread.sleep(nSecond); +U/+iI>0
} %!%G\nv
catch(Exception e) \GYh"5
{ T0BFit6
e.printStackTrace (); [kwVxaI
} ,!+>/RlJ
} -w nlJi1f
v`3q0,,
//日志 %^){Z,}M}
public static void log(String sMsg) P0O5CaR
{ )X-b|D4O
System.err.println(sMsg); g4USKJ19.
} r0kJx$f
:*|%g
2u 8z>/G
public static void log(int sMsg) iu!j#VO
{ x+Vp&
System.err.println(sMsg); 1SIhW:C
} }T=0]u4,
} S9kagiFX\
8a{S*
BeP]M1\?>
/* q#9JJWSs
**TestMethod.java >7%Gd-;l
*/ CVfQ
package NetFox; $1<V'b[E
+Hx$ABH
[1{#a {4
public class TestMethod { MX!t/&X(n
1_JtD|Jy
df@IC@`pB
public TestMethod() fNb2>1
{ ///xx/weblogic60b2_win.exe heQ<%NIA"
try{ {pJ{UJKv?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ioxsx>e<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vg@kPuOiO
SiteFileFetch fileFetch = new SiteFileFetch(bean); uNnx i
fileFetch.start(); L3[r7 b
} [/_M!&zz2
catch(Exception e){e.printStackTrace ();} H^y%Bi&^
_SU%ul
FPj j1U`C
} r[; .1,(
F-i`GMWC
8W' ,T
public static void main(String[] args) ["l1\YCi
{ }{"a}zOl
new TestMethod(); -={Z::}S"
} tMM*m
} L"|4 v
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