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)); 29E@e]Y,`
} o\Vt $
for(int i=0;i<nEndPos.length-1;i++) p[+me o
{ G6g=F+X2
nEndPos = nStartPos[i+1]; "I1M$^8n
} d}G."wnG9,
nEndPos[nEndPos.length-1] = nFileLength; 6je%LHhL
} s)ajy^6'M
} 1$!K2=%OXj
@9Pn(fd]
L,ey3i7a\
//启动子线程 61;5Yo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wn</",Gf
for(int i=0;i<nStartPos.length;i++) 1OGv+b)
{ g KY ,G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wEn&zZjx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ktJLpZ<0O
nStartPos,nEndPos,i); 79fyn!Iz<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BY2txLLB
fileSplitterFetch.start(); a[9OtZX<
} uS10P7N}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9>Z#o<*_/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ])";Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YQd&rkr
nEndPos = " + nFileLength); bI0+J)
// fileSplitterFetch[nPos.length-1].start(); ~Am %%$
17i@GnbNb
.j@n6RyN
//等待子线程结束 @ dU3d\!}
//int count = 0; OnPLz"-
//是否结束while循环 ue2nfp
boolean breakWhile = false; u,k8i:JY
ju6_L<
m9i%U
while(!bStop) cB'4{R@e
{ F476"WF
write_nPos(); ^mb*w)-p?
Utility.sleep(500); x \{jWR%
breakWhile = true; PH=8'GN
#j5^/*XW
5?Ao9Q]@
for(int i=0;i<nStartPos.length;i++) s9dBXfm
{ !f2>6}hE
if(!fileSplitterFetch.bDownOver) OnJSu z>-
{ P+l^Ep8P
breakWhile = false; +:8YMM#9V
break; 3W WxpTU
} 1j-i nj`
} h$h`XBVZe;
if(breakWhile) f }e7g d]M
break; *wx^mB9
+Rd{ ?)2~
25KZe s)
//count++; U?C{.@#w
//if(count>4) O/"&?)[v
// siteStop(); 7im;b15j`'
} FAGVpO[
U9OF0=g
(G;*B<|A
System.err.println("文件下载结束！"); R-|]GqS}L
} P"VLGa
catch(Exception e){e.printStackTrace ();} 4r!40^:2
} FNO lR>0e
7q1l9:VYE
|pg5m*h
//获得文件长度 q/zdd3a
public long getFileSize() 1Tkdr2
{ {.)D)8`<d
int nFileLength = -1; jC7XdYp
try{ 2}#PDhn
URL url = new URL(siteInfoBean.getSSiteURL()); ZU6a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Darkj>$\
httpConnection.setRequestProperty("User-Agent","NetFox"); K6Ua~N^
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t)+dW~g
int responseCode=httpConnection.getResponseCode(); <H#K`|Ag
if(responseCode>=400) ,5WDYk-
{ 4 ETVyK|
processErrorCode(responseCode); );LwWKa
return -2; //-2 represent access is error PUArKBYM-
} 1(a\$Di
u'][3
.;s4T?j@w
String sHeader; ak&v/%N
ShxX[k
5eJd$}Lbc
for(int i=1;;i++) 6Z=H>w
{ 6.=b^6MV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1j(,VW
//Utility.log(in.readLine()); exvsf|
sHeader=httpConnection.getHeaderFieldKey(i); zt6ep=
if(sHeader!=null) aPgG+tu
{ $Q4b~
if(sHeader.equals("Content-Length")) RT9@&5>il
{ ^)I:82"|?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d_hcv|%
break; Aed"J5[a
} {F[Xe_=#"
} *4E,|IJ
else vA`.8U 0S
break; QkAwG[4
} 64@s|m*
} GC2<K
catch(IOException e){e.printStackTrace ();} :gC2zv
catch(Exception e){e.printStackTrace ();} 5#PhaVc
tp&iOP6O
4dAhJjhgD
Utility.log(nFileLength); }+1oD{
f|)t[,c
NST6pu\,U
return nFileLength; ~Otf "<
} T~E83Jw
`}l%Am
ualtIHXK)
//保存下载信息（文件指针位置） cCs:z
private void write_nPos() WBIS
{ 4vphLAm
try{ Wi<Fkzj
output = new DataOutputStream(new FileOutputStream(tmpFile)); NM]/OKs'H
output.writeInt(nStartPos.length); lB-7.
for(int i=0;i<nStartPos.length;i++) n66_#X
{ =G :H)i
// output.writeLong(nPos); v;7u"9t
output.writeLong(fileSplitterFetch.nStartPos); <}%*4mv
output.writeLong(fileSplitterFetch.nEndPos); DFMWgBL
} -M}iDBJx>#
output.close(); AH+J:8k
} 0Og =H79<
catch(IOException e){e.printStackTrace ();} I6_+3}Hm{
catch(Exception e){e.printStackTrace ();} oxZ(qfjS
} kLP^q+$u)!
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ej `$-hBBV
//读取保存的下载信息（文件指针位置） t~Ax#H
private void read_nPos() &XP 0
{ kCV OeXv
try{ DQd&:J@?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8*X8U:.0o
int nCount = input.readInt(); ewY X\
nStartPos = new long[nCount]; ececN{U/
nEndPos = new long[nCount]; 9)qx0
for(int i=0;i<nStartPos.length;i++) V'B 6C#jT
{ FgxQ}VvlH
nStartPos = input.readLong(); 0Qz \"gr
nEndPos = input.readLong(); v)06`G
} l3,|r QD
input.close(); 3 0Z;}<)9
} P%c<0y"O:>
catch(IOException e){e.printStackTrace ();} 9^n ]qg^
catch(Exception e){e.printStackTrace ();} rcOmpgew
} ~p.23G]x
R\^tr
[(XKqiSV
private void processErrorCode(int nErrorCode) X%sc:V
{ 4Bz~_
System.err.println("Error Code : " + nErrorCode); Y]PZ| G)
} bZ)Jgz
+?8nY.~,'
o,L!F`W
//停止文件下载 WW.=>]7;
public void siteStop() 6 S8#[b
{ [(hENX}o:
bStop = true; (Jm_2CN7X
for(int i=0;i<nStartPos.length;i++) E+gUzz5
fileSplitterFetch.splitterStop(); qluyJpt
@({65gJ*
1<*-,f
} " 1Bn/Q
} [M.Vu
//负责部分文件的抓取 > 01k u
**FileSplitterFetch.java I/adzLQ
*/ J GdVSjNC
package NetFox; uAP|ASH9T
Lqt]
R!O'DM+
import java.io.*; d;z`xy(C
import java.net.*; 8miIlB
XX =A1#H
|<E%hf
public class FileSplitterFetch extends Thread { TUT>*
E?V:dr
^>>Naid
String sURL; //File URL ?Gb 18m
long nStartPos; //File Snippet Start Position li'#< "R?'
long nEndPos; //File Snippet End Position =8]'/b
int nThreadID; //Thread's ID \6o ~ i
boolean bDownOver = false; //Downing is over d%<Uh(+:
boolean bStop = false; //Stop identical W\"cp[b
FileAccessI fileAccessI = null; //File Access interface E4PP&'
[30< 0
*N't ;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /2c?+04+
{ ^;'3(m=
this.sURL = sURL; n`6vM4rM)
this.nStartPos = nStart; v^vEaB
this.nEndPos = nEnd; )gE:@3
nThreadID = id; .gB#g{5+J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bAgKOfT
} q o'1Pknz
GYBM]mW^ W
fQ<V_loP.@
public void run() [bAv|;
{ m2_B(-
while(nStartPos < nEndPos && !bStop) W6Hiqu+
{ (t <Um Vd
8u>E(Vmpu
PpbW+}aCF
try{ SkY|.w.
URL url = new URL(sURL); %FwLFo^v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PffRV7qU0
httpConnection.setRequestProperty("User-Agent","NetFox"); BQm H9g|2
String sProperty = "bytes="+nStartPos+"-"; M$w^g8F27H
httpConnection.setRequestProperty("RANGE",sProperty); ]LD@I;(_
Utility.log(sProperty); PS>k67sI
&.d~ M1Mz
CEwG#fZ
InputStream input = httpConnection.getInputStream(); )UWE.oBI
//logResponseHead(httpConnection); sYvO"|
`A#r6+
k1X<jC]P
byte[] b = new byte[1024]; 3o6N&bQ b
int nRead; Qq5)|m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]R0^ }sI
{ f F?=W
nStartPos += fileAccessI.write(b,0,nRead); 7[Y<5T]
//if(nThreadID == 1) K2&pTA~OR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C6GYhG]
} SwQb"
TK'(\[E
t&ngOF
Utility.log("Thread " + nThreadID + " is over!"); E_FseR6
bDownOver = true; K{N#^L!
//nPos = fileAccessI.write (b,0,nRead); mI}'8.
} @L`t/OD
catch(Exception e){e.printStackTrace ();} .Emw;+>
} )5hS;u&b
} @}#$<6|
m|'TPy
D9JT)a
//打印回应的头信息 ?!Y2fK=h0
public void logResponseHead(HttpURLConnection con) &}rh+z
{ HdVGkv/
for(int i=1;;i++) B6,"S5@
{ 9v^MZ^Y{
String header=con.getHeaderFieldKey(i); 8%Pjx7'<
if(header!=null) zL1H[}[z+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8He^j5
Utility.log(header+" : "+con.getHeaderField(header)); "Y4tt0I
else *2@Ne[dYEF
break; g!4"3Dtdg
} \ B<(9
} UA}k"uM
d!!5'/tmS
u"tv6Qp
public void splitterStop() A2]N :=
{ "#(]{MY
bStop = true; IS"UBJ6p
} Yk[yG;W
9;kWuP>k4u
'R= r9_%
} -]HO8}-Rjs
!<@Zf4m
6:J @
/* xj(&EGY:
**FileAccess.java \#
*//文件访问(定位，写) ?$9C[Kw`
package NetFox; co#%~KqMu
import java.io.*; T5o9pmD
3. fIp5g
om|M=/^
public class FileAccessI implements Serializable{ yjc:+Y{5'
!\^c9Pg|v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zS]Yd9;X1
RandomAccessFile oSavedFile; ,0;E_i7
long nPos; rJ K~kKG
@:X~^K.
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public FileAccessI() throws IOException \%f4)Qb
{ G ?H`9*y
this("",0); (yn!~El3
} W%@6D|^
| \C{R
n"$D/XJO
public FileAccessI(String sName,long nPos) throws IOException Cj,fP[p#7
{ USfOc
oSavedFile = new RandomAccessFile(sName,"rw"); 0(h *<g:
this.nPos = nPos; "EDn;l-Q
oSavedFile.seek(nPos); ' w!o!_T6
} j8YMod=
R@u6mMX{N,
ySL 31%
public synchronized int write(byte[] b,int nStart,int nLen) JstX# z
{ A7 E*w
int n = -1; ;q59Cr75
try{ _\1wLcFj
oSavedFile.write(b,nStart,nLen); s+$l.aIO!
n = nLen; |U>BXX P
} \|L@
catch(IOException e) !Yz~HO,u+
{ ; P&Ka
e.printStackTrace (); &Dgho
} >x eKO2o
]+{Cy\*kR
3#j%F
return n; ~ucOQVmz@
} 80x %wCY`
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j_H{_Ug
} V#'sH
b`usRoD{+
C7[_#1Oz
/* uI}S9
**SiteInfoBean.java j*Ta?'*
*/ lc,{0$ 1<
package NetFox; {+0]diD
hHm&u^xY
Ks(+['*S
public class SiteInfoBean { k3da*vwE
zQMsS
>2_BL5<S
private String sSiteURL; //Site's URL (_^g:>)Cs
private String sFilePath; //Saved File's Path bN`oQ.Z 4
private String sFileName; //Saved File's Name ;e_dk4_
private int nSplitter; //Count of Splited Downloading File u-=S_e
O5CIK}A
i/2OE&*O[
public SiteInfoBean() VLQDktj&
{//nSplitter的缺省值为5 iW(HOsA
//default value of nSplitter is 5 Og4 X3QG
this("","","",5); @Kd1|K
} 'ejuzE9
R rs?I,NV
/pan{.< k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s#/JMvQ#
{ 16_HO%v->
sSiteURL= sURL; iNUisl
sFilePath = sPath; 0(VH8@h`O
sFileName = sName; zmQ V6o=k
this.nSplitter = nSpiltter; ^>gRK*,
8 k9(iS
&PI}o
} {+r pMUs#
j#S>8: G
V@&zn8?
public String getSSiteURL() ,>A9OTSN\
{ z'=*pIY5f
return sSiteURL; FY)vrM*yh
} JR|yg=E
dd>|1'-]
O`~G'l&@T
public void setSSiteURL(String value) Po'yr]pr
{ Z#BwJHh
sSiteURL = value; dE!{=u(!i
} }00mJ]H(
<?kr"[cQeP
jhjGDF
public String getSFilePath() v|t_kNX;v*
{ {:xINQ=}D
return sFilePath; UeV2`zIg`
} ^crk8O@Fw
4j|]=58
%Js3Y9AL C
public void setSFilePath(String value) EgM.wQHR]
{ 3Wxl7"!x m
sFilePath = value; G,9osTt/
} kD dY i7g>
?6+GE_VZ
QFU;\H/
public String getSFileName() I1^0RB{~
{ ,uqSq
return sFileName; v^2K=f[nE
} ,u^i0uOg
6pDb5@QjTy
dy N`9
public void setSFileName(String value) 2c@4<kyfP
{ Yf&x]<rkCp
sFileName = value; V^B'T]s
} P0uUVU=B|
<^6|ZgR
0M(\xO
public int getNSplitter() P9; =O$s
{ h~{TCK+I
return nSplitter; Qc#<RbLL
} YbB8D-
F?&n5R.
rU`#3}s
public void setNSplitter(int nCount) 'qwFVP
{ a<7Ui;^@
nSplitter = nCount; Q4\EI=4P]
} hE0 p>R8
} 0FD#9r
\M(0@#-$C
$Q*h+)g<
/* \L}aTCvG
**Utility.java &+;z`A'|8
*/ vggyQf%
package NetFox; <gRv7 ?V[z
3Xyu`zS&
wR +C>
public class Utility { q|BR-0yi
,0O9!^
'AU(WHf
public Utility() e2CjZ"C
{ :td6Mywl
%Ez=
Q$Qs$
} 'D(|NYY
H+y(W5|2/X
//线程睡眠 rdZk2\<
public static void sleep(int nSecond) )!J0e-T-8O
{ $K>'aI;|
try{ &Iv3_T<AF
Thread.sleep(nSecond); Uu ~BErEC
} SE/GT:}
catch(Exception e) *-"DZ
{ Wm\HZ9PN
e.printStackTrace (); xR `4<
} ^[6eo8Ck>
} b$\3Y'":
XMo#LS
//日志 N@Pf\D
public static void log(String sMsg) '*H&s
{ Hh`x>{,|S
System.err.println(sMsg); de{@u<YZb
} 0V6gNEAUg
3p`*'j2R
7qj<|US
public static void log(int sMsg) 21i?$ uU
{ cnJ(Fv_F$
System.err.println(sMsg); &?C% -"|c
} s<,[xkMB
} QII-9RxX"
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A3D"b9<D
/* <nDuN*|
**TestMethod.java @H[)U/.
*/ .`qw8e}y#'
package NetFox; x&>zD0\ :\
Q${0(#Nu
=yo?]ZS
public class TestMethod { M ^gva?{
<Vucr
JwEQR
public TestMethod() @%Y$@Qb{
{ ///xx/weblogic60b2_win.exe }jTCzqHW]
try{ fui;F"+1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {jB& e,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bV c"'RQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); &L6xagR7M
fileFetch.start(); FVw;`{
} g2Pa-}{
catch(Exception e){e.printStackTrace ();} '4 T}$a"i
&Luq}^u
n<RvL^T=
} m/}(dT;
g=W1y
K[}5bjh>
public static void main(String[] args) k~ Z9og
{ d +0(H
new TestMethod(); _Q&O#f
} T^FeahA7;
} peW4J<,
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