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)); S8)6@ECC
} i(n BXV{
for(int i=0;i<nEndPos.length-1;i++) &\M<>>IB
{ QetyuhS~
nEndPos = nStartPos[i+1]; Gmh6|Dsg
} 2lRE+_qz
nEndPos[nEndPos.length-1] = nFileLength; IX 2 dic'
} @L5s.]vg=
} GA"zO,
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//启动子线程 _air'XQ&!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7,EdJ[CR$
for(int i=0;i<nStartPos.length;i++) /~;om\7r
{ D1f}g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w|8T6W|w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ORo,.#<
nStartPos,nEndPos,i); (<xl _L:*.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xr1,D5
fileSplitterFetch.start(); TKZ[H$Z
} W(,3j{d2i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _T.k/a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5}"9)LT@@w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EHX/XM
nEndPos = " + nFileLength); }w/6"MJ[n
// fileSplitterFetch[nPos.length-1].start(); 4,qhWe`/
jq12,R2+)
~-o[v-\
//等待子线程结束 78/,rp#'_
//int count = 0; =^`?O* /;
//是否结束while循环 ^ah9:}Ll
boolean breakWhile = false; xh9Os <
f#b;s<G
])NQzgS
while(!bStop) aLt2fB1)
{ 6~c:FsZ)
write_nPos(); :[.**,0R
Utility.sleep(500); 'yR)z\)
breakWhile = true; =/MA`>
jdAjCy;s!
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for(int i=0;i<nStartPos.length;i++) &'<e9
{ YGf<!
if(!fileSplitterFetch.bDownOver) cMp#_\B
{ eNX!EN(^
breakWhile = false; x /E<@?*:
break; %{;1i
} :pvJpu$]
} 9B?-&t
if(breakWhile) {>n\B~*,"C
break; %,Lv},%Y
M.?[Xpa
B6xM#)
//count++; oZ,_G,b^
//if(count>4) EohvP[i
// siteStop(); K:(E"d;
} $bsD'Io
S>V+IKW;(
I> BGp4AQ
System.err.println("文件下载结束！"); 0Tq=nYZA
} 2$s2u;
catch(Exception e){e.printStackTrace ();} =C 7WQ
} fv/Nf"
qvG@kuz8g5
xY>@GSO1
//获得文件长度 rc`}QoB)R
public long getFileSize() _UGR+0'Q\
{ 5)iOG#8qJ
int nFileLength = -1; $*hqF1Q
try{ z1S p'h$
URL url = new URL(siteInfoBean.getSSiteURL()); pq$-s7#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hU6oWm
httpConnection.setRequestProperty("User-Agent","NetFox"); iR]K!j2
M)1Y7?r]
}WDzzjDR+
int responseCode=httpConnection.getResponseCode(); k{ ~0BK
if(responseCode>=400) ]+A%37
{ Wmc@: (n
processErrorCode(responseCode); p(Ux]_s%
return -2; //-2 represent access is error +o-jMvK9
} ???`BF[|
+^|_vq^XR
Lv UQ&NmY
String sHeader; T7~H|%
@L?KcGD
'8w>=9Xl
for(int i=1;;i++) AX;!-|bW
{ I>JBGR`j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MUn(ZnQy|
//Utility.log(in.readLine()); |ya.c\}q
sHeader=httpConnection.getHeaderFieldKey(i); #pcgfVl
if(sHeader!=null) W`v$-o-
{ @8*lqV2
if(sHeader.equals("Content-Length")) Yhte&,D"
{ n#^ii/H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h?'~/@
break; 'e/wjV
} @L$!hTaP
} dVe,;?+A
else Q>(a JF
break; je85G`{DC
} s>*xAIx
} <.".,Na(J0
catch(IOException e){e.printStackTrace ();} i936+[
catch(Exception e){e.printStackTrace ();} V:h7}T95
f~ wgMp.W0
f0&%
Utility.log(nFileLength); \zKO5,qw
&P7Z_&34Z
!|\l*
return nFileLength; }Xvm( ;
} %+^Qs\j
#MFIsx)r
=;"=o5g_
//保存下载信息（文件指针位置） lhC hk7l
private void write_nPos() PdtL Cgd
{ 1xI
try{ YS:p(jtd
output = new DataOutputStream(new FileOutputStream(tmpFile)); _ee<i8_Va
output.writeInt(nStartPos.length); EpH_v`
for(int i=0;i<nStartPos.length;i++) jn(%v]
{ F1meftK
// output.writeLong(nPos); 9y&bKB2,
output.writeLong(fileSplitterFetch.nStartPos); J6Vx7
output.writeLong(fileSplitterFetch.nEndPos); _"*}8{|
} 6H=gura&
output.close(); 0X3yfrim
} \PWH(E9
catch(IOException e){e.printStackTrace ();} ;y_]w6|n
catch(Exception e){e.printStackTrace ();} S5V:HRj{?
} #%EHcgF
4Cv*zn
(x fN=Te,-
//读取保存的下载信息（文件指针位置） ``%yVVg}
private void read_nPos() T'{9!By,P
{ k/(]1QnW
try{ w2db=9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j#0JD!Vr
int nCount = input.readInt(); ||?@pn\
nStartPos = new long[nCount]; $<yhEvv
nEndPos = new long[nCount]; .5uqc.i"f
for(int i=0;i<nStartPos.length;i++) =*1NVi $n
{ e3ce?gk
nStartPos = input.readLong(); zz /4 ()u
nEndPos = input.readLong(); 3)yL#hXg)
} |kP utB
input.close(); VD<z]@
} 2vWn(6`
catch(IOException e){e.printStackTrace ();} Q8MIpa!:
catch(Exception e){e.printStackTrace ();} 7Ja*T@ !h
} ;tSAQ
j+@3.^vK
AJm$(3?/D
private void processErrorCode(int nErrorCode) tv26eK 38
{ ,J8n}7aI
System.err.println("Error Code : " + nErrorCode); ^qnmKA>"F
} m7DKC,
J\P6
*MB>,HU
//停止文件下载 g(Q1d-L4e
public void siteStop() z_N";Rn
{ ,yA[XAz~U
bStop = true; S*$?~4{R
for(int i=0;i<nStartPos.length;i++) {`Gd
fileSplitterFetch.splitterStop(); d$jwh(Ivs
}opw_h+/F
Ulx]4;uzf
} fbU3-L?
} lLDZ#'&An
//负责部分文件的抓取 ] |nW
**FileSplitterFetch.java R3;%eyu
*/ lPI~5N8
package NetFox; s M*ay,v;
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/0 4US5En
import java.io.*; P:t .Nr"
import java.net.*; a eeor
MM_:2 ^P)
+D:8r|evH
public class FileSplitterFetch extends Thread { -rn6ZSD)
Q2D!Agq=D
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String sURL; //File URL tM^4K r~o,
long nStartPos; //File Snippet Start Position "L:4 7!8
long nEndPos; //File Snippet End Position &iVdqr1,
int nThreadID; //Thread's ID 2 U]d1
boolean bDownOver = false; //Downing is over r34MDUZdI
boolean bStop = false; //Stop identical RFyMRE!?
FileAccessI fileAccessI = null; //File Access interface y;uR@{
31@Lr[!
c~?Zmdn:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r`.N?
{ [IQ|c?DxpL
this.sURL = sURL; msM1K1er
this.nStartPos = nStart; |PlNVd2
this.nEndPos = nEnd; Hddc-7s
nThreadID = id; kQ}n~Hn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >a,D8M?
} c%J6!\
JD~;.3$/k
,_fz)@)
public void run() 4a"Fu<q
{ u}gavG l
while(nStartPos < nEndPos && !bStop) P=5+I+
{ ANy*'/f
GD{L$#i!
c&!mKMrk
try{ D**GC
URL url = new URL(sURL); Cq"KKuf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hU8Y&R)=9
httpConnection.setRequestProperty("User-Agent","NetFox"); `X}:(O^GO
String sProperty = "bytes="+nStartPos+"-"; 0n}13u=}
httpConnection.setRequestProperty("RANGE",sProperty); M[gL7-%w\
Utility.log(sProperty); yGf7k>K'
]mb8R:a1
U8w_C\Q
InputStream input = httpConnection.getInputStream(); E5d$n*A
//logResponseHead(httpConnection); Z0jgUq`r
/}(d'@8p
:Ko6.|
byte[] b = new byte[1024]; ~vFa\7sf
int nRead; ( %\7dxiK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $+!dP{
{ ba);f[>
nStartPos += fileAccessI.write(b,0,nRead); 2t-w0~O
//if(nThreadID == 1) ^,acU\}VqP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NEIkG>\7q
} >F7w]XH
>sfg`4
>H!Mx_fDL
Utility.log("Thread " + nThreadID + " is over!"); )rD!4"8/A
bDownOver = true; x8PT+KC
//nPos = fileAccessI.write (b,0,nRead); jdP)y]c
} Dj&~x
catch(Exception e){e.printStackTrace ();} rP3HR5
} 8w&-O~M
} UJ)pae
2gPqB*H
DH-M|~.sf^
//打印回应的头信息 IW3k{z
public void logResponseHead(HttpURLConnection con) %w*)7@,+-
{ fkBL`[v)4
for(int i=1;;i++) hMDd*<%l
{ ?Gki0^~J
String header=con.getHeaderFieldKey(i); ?;XEb\Kf
if(header!=null) h'):/}JPl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2Wz8E2.
Utility.log(header+" : "+con.getHeaderField(header)); _\}'5nmw\
else d,V#5l-6
break; ,Of^xER`
} O1J&Lwpk,
} N1c=cZDV
i2~uhGJ
f"QiVJq
public void splitterStop() (+> 2&@@<
{ [1VA`:?W
bStop = true; QPJ\Iu@D$
} d(T4Kd$r
{r,Uik-nL
wA=r]BT
} ,#A(I#wL~
Ymk?@mV4
Gt9$hB7
/* \k.`xG?
**FileAccess.java ?Z7`TnG$uf
*//文件访问(定位，写) r~t`H*C)}
package NetFox; jxh:z
import java.io.*; WQK<z!W5
m+kP"]v
Fb5U@X/vE
public class FileAccessI implements Serializable{ jT{T#_
sgX!4wG&Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2bp@m;g$
RandomAccessFile oSavedFile; LL^KZ-
long nPos; K4c:k; V
0bg"Q4
94u{k1d x
public FileAccessI() throws IOException .+9hm|
{ *@2Bh4
this("",0); VY0.]t
} n~N>;mP
tIsWPt]Y
Zd*$^P,|
public FileAccessI(String sName,long nPos) throws IOException };/QK*
{ zUfq.
oSavedFile = new RandomAccessFile(sName,"rw"); /`*{57/3
this.nPos = nPos; =}^NyLE?
oSavedFile.seek(nPos); eUyF<j
} Jl Do_}
> ;,S||
-/yqiC-yx
public synchronized int write(byte[] b,int nStart,int nLen) %tCv-aX4
{ RgJ@J/p"
int n = -1; [XfR`@
try{ U v2.Jo/Q
oSavedFile.write(b,nStart,nLen); ?[D3-4
n = nLen; F"@%7xy
} x84!/n^z
catch(IOException e) -aoYoJ '
{ 4T@:_G2b
e.printStackTrace (); _gvFs%J
} ;[v!#+yml
R'Sd'pSDN
h)KHc/S
return n; jEc_!Q
} YG "Ta|@5
L:R4&|E/t
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} IGdiIhH~2
^|]&"OaB Z
BQ@7^E[
/* }u Y2-l
**SiteInfoBean.java 6K/RO)
*/ U<Pjn)M~B
package NetFox; p8rh`7
l& :EKh
tcD7OC:"6
public class SiteInfoBean { ;FPx
Pf*6/7S:
b/SBQ"B%
private String sSiteURL; //Site's URL p@<Q?
private String sFilePath; //Saved File's Path hnnB4]c
private String sFileName; //Saved File's Name 2w?q7N%
private int nSplitter; //Count of Splited Downloading File 3<0b_b
p~pD`'%
]g_VPx"
public SiteInfoBean() 6#=jF[
{//nSplitter的缺省值为5 *Rgr4-eS
//default value of nSplitter is 5 H|9t5
this("","","",5); aO6\e>
} &qv~)ZM$
Y0LZbT3
jUe@xis<T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o2/:e
{ s\*L5{kiSl
sSiteURL= sURL; 4>JSZ6i#n
sFilePath = sPath; KkvcZs'4m
sFileName = sName; L4By5)
this.nSplitter = nSpiltter; o3J#hQrl
H;Wrcf2
:6n#y-9^1
} o+A7hBM^
mw@Pl\=
+C(-f
public String getSSiteURL() H4$qM_N
{ 'o AmA=
return sSiteURL; GABZsdFZ!
} xL}i9ozZ
w^yb`\$
l45/$G7
public void setSSiteURL(String value) LUOjaX
{ JGs:RD'
sSiteURL = value; j-<]OOD
} j3j?2#vR
du65=w4E!
?OD$`{1
public String getSFilePath() m%'nk"p9
{ L9GLjRp-
return sFilePath; q+g,?;Yx
} b--=GY))F
~Y 6'sM|
Y(Q 0m|3P
public void setSFilePath(String value) >O'\ jp}$l
{ _~kw^!p>Kr
sFilePath = value; 'Wlbh:=$
} bJd|mm/v
=i/Df?
{)YbksrJ{
public String getSFileName() @rl5k(
{ r- 8Awa
return sFileName; 7!O"k#
} Z,&O8Jelf
|OeyPD#
_v!7 |&\
public void setSFileName(String value) $)lkiA&;
{ KVi6vdgD
sFileName = value; ?N#I2jxaD
} !xs}CxEyA
+! 1_Mt6
1d^~KBfv
public int getNSplitter() oD)x\ )t8
{ uEPp%&D.+
return nSplitter; rQ*+ <`R}
} (i "TF2U,<
fSo8O
m#"_x{oa
public void setNSplitter(int nCount) v%tjZ5x
{ <Q[%:LD
nSplitter = nCount; 3Y#Q'r?
} `3TR`,=
} 7B?Y.B
7)?C+=,0
H2X_WSwm
/* @0+\:F
**Utility.java P1#g{f
*/ 5Xq+lLW>
package NetFox; G%F#I
B=SA +{o
corm'AJ/
public class Utility { |J$A%27
xUJ(tG3
(zhZ}C,VF
public Utility() vNO&0~
{ B'Yx/c&n
0s n$QmW:
L]Tj]u)
} (,At5T
w,%"+tY_
//线程睡眠 ]LE,4[VxRz
public static void sleep(int nSecond) 35h|?eN_m!
{ -l[H]BAMXy
try{ K,4Ig!
Thread.sleep(nSecond); ,&[o:jTk
} X5WA-s(?0
catch(Exception e) [P2>KQ\
{ vo/x`F'ib
e.printStackTrace (); pY&6p~\p
} g=:o'W$@
} #2=l\y-#
qq)5)S
//日志 ZflB<cI
public static void log(String sMsg) NlYuT+
{ ko%mZ0Y
System.err.println(sMsg); rwWOhD)RU
} 5Tn<
P~7(x7/7~
lMv6QL\>'
public static void log(int sMsg) \VPw3
{ vfSPgUB)
System.err.println(sMsg); ,='Ihi
} VL#:oyWA
} z,Xj$wl
I:dUHN+@L5
tI^91I
/* 8\J$\Edv
**TestMethod.java l;-2hZ
*/ Tzd#!Lvm:,
package NetFox; ~-"CU:$o
h;=~%2Y
F:zmO5L5
public class TestMethod { =Jp:dM*
O%t? -h
= MByD&o`
public TestMethod() 5;`Ot2
{ ///xx/weblogic60b2_win.exe kEh9J>|M
try{ {-)^?Zb @
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /&6{}n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [3dGHf;miw
SiteFileFetch fileFetch = new SiteFileFetch(bean); @(R=4LL
fileFetch.start(); g0f4>m
} VEV?$R7;
catch(Exception e){e.printStackTrace ();} 1 |z4]R,<
jHEP1rNHE
XT/t\\Z`U
} :EW1I>}_
RFM;?!S
A6z2KVk
public static void main(String[] args) S{llpp{E
{ 1 -Z&/3T]
new TestMethod(); O0}uY:B
} 7\@c1e*e
} UDHOcb
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