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)); w$7*za2
} ?EeHeN_
for(int i=0;i<nEndPos.length-1;i++) E#_TX3B
{ 'Z-jj2t}
nEndPos = nStartPos[i+1]; Gt[!q\^?
} aIk%$Mat
nEndPos[nEndPos.length-1] = nFileLength; iuq-M?1
} S5'BXE,
} ;h3uMUCml
un[Z$moN"
im_W0tGvF
//启动子线程 +GWeu0b(~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j]6j!.1
for(int i=0;i<nStartPos.length;i++) NrTQ}_3)
{ RaAi9b[/S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >U9*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z@$7T:H>
nStartPos,nEndPos,i); jGEUl=W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l?B\TA^
fileSplitterFetch.start(); jjkiic+tDN
} _ 9Tv*@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $CO^dFf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dapQ5JT/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }}Eko7'^
nEndPos = " + nFileLength); H.j(hc'
// fileSplitterFetch[nPos.length-1].start(); :h N*
rU5gQq;
jGd{*4{3+
//等待子线程结束 G6Z2[Ej1
//int count = 0; S(Xab_DT)H
//是否结束while循环 f>5{SoM
boolean breakWhile = false; m"~$JA u
cxrUk$f
5FnWlFc
while(!bStop) 4W~pAruwr
{ ld4QhZia
write_nPos(); S[{#AX=0
Utility.sleep(500); ju(&v*KA
breakWhile = true; J(h=@cw
IC/'<%k
yEy} PCJ&
for(int i=0;i<nStartPos.length;i++) Ta%{Wa\U9z
{ L\5j"] }`
if(!fileSplitterFetch.bDownOver) ^x4I
{ _UYt
breakWhile = false; s<xD$K~rM
break; WsQo+Ua
} `pE~M05
} f$NudG!S
if(breakWhile) G{i}z^n
break; !t{3IE
6?Rm>+2>v
EMmNlj6
//count++; fnG&29x
//if(count>4) ,+KZn}>
// siteStop(); pcv(P
} Z'>Xn^
( N~[sf?&
SY["dcx+
System.err.println("文件下载结束！"); k;R*mg*K
} c</d1xT
catch(Exception e){e.printStackTrace ();} {%'(IJ|5z
} /,f*IdB
ce/Rzid
+iir]"8
//获得文件长度 `B"=\0
public long getFileSize() v-3In\T=^
{ AiykIER/
int nFileLength = -1; }>=k!l{
try{ bBc<yaN
URL url = new URL(siteInfoBean.getSSiteURL()); t]#y}V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @>_`g=
httpConnection.setRequestProperty("User-Agent","NetFox"); `$jc=ZLm
aIpDf|~
G)';ucs:,
int responseCode=httpConnection.getResponseCode(); &7!&]kA+
if(responseCode>=400) u{,e8. Z
{ L@2T
processErrorCode(responseCode); p[VBeO^%
return -2; //-2 represent access is error V{p*N*
} 'xm_oGWE
~z$vF
57Q^"sl
String sHeader; ".O+";wk
\]e"#"v}}_
+u#;k!B/>
for(int i=1;;i++) D'F=v\P
{ p [4/Nq,c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^\Nsx)Y;
//Utility.log(in.readLine()); w?d~c*4+
sHeader=httpConnection.getHeaderFieldKey(i); 5e~\o}]
if(sHeader!=null) hn#i,XnY
{ N W :_)1
if(sHeader.equals("Content-Length")) UB }n=
{ Mp^%.m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8bLA6qmM\
break; "jH=O(37
} X}Bo[YoY$
} 7"Sw))H|
else d!5C$C/x
break; NJ^`vWi
} w>>)3:Ytd
} `=g9Rg/<
catch(IOException e){e.printStackTrace ();} S#Tc{@e
catch(Exception e){e.printStackTrace ();} K9B_o,
G.OAzA13!t
`[p*qsp_
Utility.log(nFileLength); 9>\P]:
q{5wx8_U
{L5!_]6
return nFileLength; (xf_
} r63_|~JVB<
DvCs 5
G=W!$(:
//保存下载信息（文件指针位置） sgp5b$2T.
private void write_nPos() j/`-x
{ e>vV8a\
try{ +e?mKLw14
output = new DataOutputStream(new FileOutputStream(tmpFile)); eR PmN
output.writeInt(nStartPos.length); p%toD{$
for(int i=0;i<nStartPos.length;i++) 8d|omqe~P
{ *{8<4CVv
// output.writeLong(nPos); bCr) 3,
output.writeLong(fileSplitterFetch.nStartPos); _xT=AF9~o
output.writeLong(fileSplitterFetch.nEndPos); S*-n%D0q5
} k~Qb"6n2
output.close(); 7\m.xWX e
} DG,CL8bv
catch(IOException e){e.printStackTrace ();} kY*3)KCp
catch(Exception e){e.printStackTrace ();} ,S5tkTa
} M24FuS
V9[-# Ti
k>y68_
//读取保存的下载信息（文件指针位置） =r=[e}&9
private void read_nPos() Pz#D9.D0
{ {j i;~9'Q
try{ c6FKpdn%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "~jSG7h
int nCount = input.readInt(); 0`.3`Mk
nStartPos = new long[nCount]; F4'g}yOLd
nEndPos = new long[nCount]; v'nM=
for(int i=0;i<nStartPos.length;i++) ]H<5]({F
{ &$F4/2|b%
nStartPos = input.readLong(); `##qf@M
nEndPos = input.readLong(); ~nJcHJ1nb4
} SQ!wq
input.close(); ,RIGV[u
} Q;{[U!\:
catch(IOException e){e.printStackTrace ();} gZ%wmY
catch(Exception e){e.printStackTrace ();} ,_;+H*H>"
} l^aG"")TH.
`X[L62D
m8'B7|s
private void processErrorCode(int nErrorCode) I{Hl2?CnI,
{ y3l3XLI*b
System.err.println("Error Code : " + nErrorCode); i(P/=B
} ?O(KmDH
4|*b{Ni
t I}@1
//停止文件下载 Ah:!
public void siteStop() ?&#z3c$}
{ &Fo)ea
bStop = true; ,4W|e!
for(int i=0;i<nStartPos.length;i++) dYEF,\Z'
fileSplitterFetch.splitterStop(); .BN~9w
N!Dc\d=8q]
B;Pws$J
} %\6ns
} P'f0KZL;
//负责部分文件的抓取 ~XAtt\WS
**FileSplitterFetch.java *V+6409m
*/ ]-h$CJSY
package NetFox; ^.bYLF
bB^% O^:
sute%6yM
import java.io.*; ^Q!qJav
import java.net.*; )6mx\t
wq&|V
[pMJ9 d$
public class FileSplitterFetch extends Thread { xbJ@z{
Wy^43g38'p
w5*?P4P
String sURL; //File URL P<P4*cOV
long nStartPos; //File Snippet Start Position )zw}+z3st
long nEndPos; //File Snippet End Position B.wihJVDg
int nThreadID; //Thread's ID V_Z~$
boolean bDownOver = false; //Downing is over }p-<+sFo
boolean bStop = false; //Stop identical Mda~@)7$
FileAccessI fileAccessI = null; //File Access interface @Dc?fyY*o<
\2cbZQx
jP'.a. ^o$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wI'8B{[
{ yNp l0 d
this.sURL = sURL; 3/a$oO
this.nStartPos = nStart; Co6ghH7T
this.nEndPos = nEnd; weQC9e~d{-
nThreadID = id; Ju5<wjQR\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >C""T`5]
} XVXiiQ^
BLxtS
gQy{OU
public void run() x`N_tWZ
{ jR~2mf!h*e
while(nStartPos < nEndPos && !bStop) e*5TZ7.
{ QuFcc}{<]
'G1~\CT
nLK%5C
try{ jxA`RSY
URL url = new URL(sURL); O8BxXa@5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <3\t J
httpConnection.setRequestProperty("User-Agent","NetFox"); $47cKit|k:
String sProperty = "bytes="+nStartPos+"-"; \(UEjlo
httpConnection.setRequestProperty("RANGE",sProperty); GCx1lm
Utility.log(sProperty); Jp)>Wd
n]&/?6}
ow:}NI
InputStream input = httpConnection.getInputStream(); F@Bh>Vb
//logResponseHead(httpConnection); d;(&_;
s_Y1rD*B
`jY*0{
byte[] b = new byte[1024]; yjCY2T E
int nRead; 9G(.=aOj,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hb&-pR@e\?
{ `_{'qqRhe
nStartPos += fileAccessI.write(b,0,nRead); 3md yY\+&
//if(nThreadID == 1) P;jl!o$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E<]l]?
} ?>47!):-*
#"|Y"#@k
arf`%9M
Utility.log("Thread " + nThreadID + " is over!"); {E!"^^0`
bDownOver = true; 1M&n=s _
//nPos = fileAccessI.write (b,0,nRead); a&YD4DQ05
} }>:v
catch(Exception e){e.printStackTrace ();} _2{i}L
} .S/W_R
} dP0!?J Y
/|] %0B
:CEhc7gU
//打印回应的头信息 >W2Z]V
public void logResponseHead(HttpURLConnection con) G hH0-g{-
{ e*gCc7zz
for(int i=1;;i++) 9TGjcZ1S'
{ Qxj &IX
String header=con.getHeaderFieldKey(i); u?[P@_i<
if(header!=null) ,6rg00wGE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kM>0>fkjE
Utility.log(header+" : "+con.getHeaderField(header)); I^ W
else @DK,ka(
break; [.tqgU
} \ ?['pB
} (mXV5IM
,2u-<8
& i|x2; v
public void splitterStop() 4)Y=)#=
{ W2h^ShG
bStop = true; 061@N=p8
} nIVPh99
btb-MSkO
V.J[Uwf
} d#7 z N
ji{V#
b\~rL,7(
/* qA:CV(Z
**FileAccess.java . (*V|&n
*//文件访问(定位，写) K V^`
package NetFox; m;o \.s
import java.io.*; *=}$@OS
Gad!}dz
Y}(#kqh>
public class FileAccessI implements Serializable{ ]5D?Sc#-
_5#f9,m1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]t_AXKd
RandomAccessFile oSavedFile; (_-<3)q4
long nPos; 'LIJpk3J
Q%~b(4E^7P
{>>ozB.
public FileAccessI() throws IOException y6Xfddd61
{ M9*7r\hqYV
this("",0); <x DD*u
} ^.jIus5
PIP2(-{ai
l<)(iU
public FileAccessI(String sName,long nPos) throws IOException ]od]S8$5
{ g':mM*j&
oSavedFile = new RandomAccessFile(sName,"rw"); P7d" E
this.nPos = nPos; 4lC:svF
oSavedFile.seek(nPos); zllY$V&<!
} l){l*~5zl2
7~TE=t
t6_6Bl:
public synchronized int write(byte[] b,int nStart,int nLen) 1g{`1[.QO
{ 0rY<CV;fZ
int n = -1; 9ZUG~d7_
try{ JE,R[` &
oSavedFile.write(b,nStart,nLen); E,E:WuB
n = nLen; D8slSX`6j
} O-:#Q(H!
catch(IOException e) yJ8WYQQMG
{ nab:y(]$/
e.printStackTrace (); jy{T=Nb
} x, a[ p\1
95^w" [}4Q
h";G vjy
return n; A- IpE
} Jis{k$4
YMLo~j4J
1eI>Yy>}
} *\m 53mb
AS`0.RC-
Hk8:7"4Q
/* F6Zl#eL
**SiteInfoBean.java MGX %U6
*/ NS6Bi3~
package NetFox; -QCo]:cp
S(mJ;C
j#y_#
public class SiteInfoBean { t*y4)I !gR
HY9H?T
kvv-f9/-
private String sSiteURL; //Site's URL z~+_sTu
private String sFilePath; //Saved File's Path r]Da4G^
private String sFileName; //Saved File's Name qrO]t\
private int nSplitter; //Count of Splited Downloading File b,/fz6 {N
^"K
yAR''>
public SiteInfoBean() 0}hN/2}&
{//nSplitter的缺省值为5 fm87?RgXD
//default value of nSplitter is 5 3G8BYP
this("","","",5); DzO0V"+H}k
} E*>tFw&[
D<5)i)J"
h=YY> x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i68'|4o
{ $4'I3{$
sSiteURL= sURL; 5.F.mUO
sFilePath = sPath; @no]*?Gpa
sFileName = sName; %m!o#y(hD`
this.nSplitter = nSpiltter; h1G]w/.ws
b|n%l5 1
}b2U o&][
} -w=rNlj
*_b4j.)ax,
b*qkox;j
public String getSSiteURL() %~J90a
{ lF5;Kc
return sSiteURL; v<_}Br2I[
} I:uxj%
F}<&@7kF
<<LmO-92
public void setSSiteURL(String value) n_AW0i.
{ Y1+4ppZ
sSiteURL = value; ygS*))7 r
} $$<9tqA
SG |!wH^
Crh5^?
public String getSFilePath() ~ygiKsD6b
{ [=u8$5/a
return sFilePath; Q#urx^aw
} JM -Tp!C>
"v/^nH
)FT~gl%
public void setSFilePath(String value) 5H:NY|
{ -]~U_J]
sFilePath = value; >pO[S[
} j\q1b:pE
wd~e3%JM
EK_NN<So#
public String getSFileName() TgJx%
{ %MU<S9k
return sFileName; 1sYwFr5
} X&MO}
,f0cy\.?
\K`AO{ D@
public void setSFileName(String value) p*_g0_^
{ HGfYL')Z
sFileName = value; +VDwDJ)lG
} dP T)&
f|WNPFQ$x
JVwYV5-O<0
public int getNSplitter() E0\ '
{ qc|;qPj
return nSplitter; E,shTh%&~
} \yNjsG@,
y7wy9+>l
i|Lir{vW
public void setNSplitter(int nCount) rl'YyO}2
{ :IV4]`
nSplitter = nCount; {a `kPfP
} :m_0WT
} :RzcK>Gub=
5ap}(bO
Y~dRvt0_w
/* )M#~/~^f+
**Utility.java <d#9d.<
*/ }C"EkT!F
package NetFox; 60[f- 0X
8xDSeXh;
jkQv cU
public class Utility { &.an-
)AXTi4MNp
;T/W7=4CZ
public Utility() 8II-'%S6q
{ -0YS$v%au>
0@C`QW%m
g % q7
} 8?W\kf$
!9356) cV
//线程睡眠 6aK'%K
public static void sleep(int nSecond) !ceuljd]
{ LDBxw
try{ [ 8N1tZ{`
Thread.sleep(nSecond); "}*P9-%
} jeN_ sm81b
catch(Exception e) ?CAP8_
{ w:r0>
e.printStackTrace (); SLSJn))@!
} L q'*B9
} x@m"[u
ZL#4X*zT
//日志 \s`'3y
public static void log(String sMsg) G2ZF`WQ
{ %N|7<n<S
System.err.println(sMsg); }%| (G[
} yb*SD!
E+dr\Xhv
DvF`KHsy
public static void log(int sMsg) .r[DqC
{ szF[LRb
System.err.println(sMsg); %.pX!jL
} (=CV")tF
} *^=`HE89S
llhJ,wD
(nbqL+
/* 6NZ3(
**TestMethod.java qdCa]n!d
*/ '-D-H}%;}M
package NetFox; X4BDl
pJ6bX4QnDX
WUQ2[)<
public class TestMethod { 1FjA
]r$S{<
Nj %!N
public TestMethod() w)&]k#r
{ ///xx/weblogic60b2_win.exe |D$U{5}Mv
try{ 58mzh82+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KG'4;Z5J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !Lb9KDk
SiteFileFetch fileFetch = new SiteFileFetch(bean); Kk!D|NKLC
fileFetch.start(); r444s8Y
} J*.Nf)i
catch(Exception e){e.printStackTrace ();} tU!"CX
Dgc[WsCEW
i'L7t!f}o
} M)Yu^
3_J9SwtN
|5V#&e\ES
public static void main(String[] args) +"?K00*(
{ jsf=S{^2
new TestMethod(); Z]1~9:7ap
} rMTtPuc2
} Cl\Vk
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