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)); zq?xY`E
} 8$X3J[_j
for(int i=0;i<nEndPos.length-1;i++) 10m|?
{ 2 1+[9
nEndPos = nStartPos[i+1]; Q~' \oWz
} UYW'pV
nEndPos[nEndPos.length-1] = nFileLength; e$`hRZ%
} plJUQk
} r/P}j4)b7
`@0AGSzUv
*ywr_9
//启动子线程 7;Q4k"h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;3bUgI}.J
for(int i=0;i<nStartPos.length;i++) 3QdCu<eBZ
{ STg} Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "i*gJFW|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V(io!8,
nStartPos,nEndPos,i); 2hryY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "*MF=VB1
fileSplitterFetch.start(); vO/3bu}
} AKk&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HN5,MD[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qFq$a9w|@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BD^1V( I/
nEndPos = " + nFileLength); 2vsV:LS.
// fileSplitterFetch[nPos.length-1].start(); /?z3*x
+~y>22Zfg
,LmP >Q.
//等待子线程结束 $ye>;Ek
//int count = 0; x_C0=Q|K3
//是否结束while循环 MtoOIkQ
boolean breakWhile = false; %@TC- xx
=2} kiLKO
vr2PCG[~
while(!bStop) F=#V/ #ia
{ &"J;
write_nPos(); wg\p&avvb
Utility.sleep(500); fd>&RbUp
breakWhile = true; )t\aB_ =
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A%^7D.j
for(int i=0;i<nStartPos.length;i++) ~$"2,&
{ 'lu3BQvfh
if(!fileSplitterFetch.bDownOver) ?`O^;f
{ S QGYH
breakWhile = false; {I?)ODx7qC
break; HXZ,"S
} \[*q~95$v
} /Bh*MH
if(breakWhile) Q[|*P ] w
break; H3ovF
;G3?Sa7+
s2 :Vm\
//count++; m&'!^{av
//if(count>4) &"hEKIqL
// siteStop(); jcBZ#|B7;
} n5IQKYrg
VRD^>Gi
MHye!T6fO\
System.err.println("文件下载结束！"); qE]e+S?57a
} $z 5kA9
catch(Exception e){e.printStackTrace ();} ;_E|I=%'E
} %:;g|PC
P*VZ$bUe5@
G|8>Q3D
//获得文件长度 QgQ$>
public long getFileSize() YgS,5::SU
{ <c!gg7@pm
int nFileLength = -1; KNj~7aTp
try{ 9tVV?Q@)
URL url = new URL(siteInfoBean.getSSiteURL()); /4+(eI7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0 ]L
httpConnection.setRequestProperty("User-Agent","NetFox"); ^M;#x$Y?
v'S5F@ln
b`^Q ':^A
int responseCode=httpConnection.getResponseCode(); :g^ mg-8
if(responseCode>=400) WY!4^<|w"
{ f#w u~*c
processErrorCode(responseCode); 1KBGML-K3
return -2; //-2 represent access is error WjM7s]ZRv
} (+/d*4
W-/V5=?
{>~9?Xwh
String sHeader; )58~2vR
o; U!{G(X
N3@[95
for(int i=1;;i++) N#t`ZC&m'
{ MtN!Xx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D3P/: 4
//Utility.log(in.readLine()); t4/ye>P &
sHeader=httpConnection.getHeaderFieldKey(i); Pt/]Z<VL
if(sHeader!=null) lI.oyR'
{ Q[K)Yd
if(sHeader.equals("Content-Length")) K:~tZ
{ |\G^:V[.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1+XM1(|c`
break; VY+P c/b
} ~a&VsC#
} J|%bRLX@>
else -)}Z $;1a
break; C"_ Roir?
} h0g?=hJq
} ~dpf1fP
catch(IOException e){e.printStackTrace ();} Qx8(w"k*
catch(Exception e){e.printStackTrace ();} Z*UVbyC
.kPNWNrw
n\JI7A}
Utility.log(nFileLength); 2l^_OrE!
,-8-Y>[
5I^;v;F
return nFileLength; `M 'tuQ M
} NRp
hwJ>IQ1
NMf#0Nz-
//保存下载信息（文件指针位置） g=@d!]Z~[
private void write_nPos() 1# z@D(
{ @|Yn~PwKs
try{ $j<KXR
output = new DataOutputStream(new FileOutputStream(tmpFile)); voN~f>
output.writeInt(nStartPos.length); LyWY\K a
for(int i=0;i<nStartPos.length;i++) [wnp]'+!
{ #9!7-!4pW
// output.writeLong(nPos); -GHd]7n
output.writeLong(fileSplitterFetch.nStartPos); {+E]c:{
output.writeLong(fileSplitterFetch.nEndPos); _ezRE"F5
} Y|Gp\
output.close(); Vdd
} HK~SD:d
catch(IOException e){e.printStackTrace ();} BI%XF 9{
catch(Exception e){e.printStackTrace ();} #u8#< ,w
} =|ODa/2p
[3nWxFz$R
{B4qeG5
//读取保存的下载信息（文件指针位置） Z${eDl6i
private void read_nPos() [YHtBM:y
{ (=Kv1 HaD
try{ o.0tD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6kdbbGO-
int nCount = input.readInt(); VwPoQ9pIS
nStartPos = new long[nCount]; "NGfT:HV
nEndPos = new long[nCount]; ]7Sf)
for(int i=0;i<nStartPos.length;i++) 8(L2w|+B<
{ NjOUe?BQ
nStartPos = input.readLong(); R]&Csr#~
nEndPos = input.readLong(); e(|Z<6
} -bHlFNRm
input.close(); oeZuvPCl
} %N fpEo
catch(IOException e){e.printStackTrace ();} :W1?t*z:[
catch(Exception e){e.printStackTrace ();} .'<K$:8@|
} H${LF.8
Y_+#|]=$B
'o#oRK{#
private void processErrorCode(int nErrorCode) QRf>lZP
{ '6&o:t
System.err.println("Error Code : " + nErrorCode); /]!2k9u\
} R#^ku)0
TEd5&Z
EGQgrwY5
//停止文件下载 Q+9:]Bt
public void siteStop() ".(vR7u'
{ D_czUM
bStop = true; \WE&5 9G
for(int i=0;i<nStartPos.length;i++) ~U"m"zpLP
fileSplitterFetch.splitterStop(); &s vg<UZ
bHv"!
?{B5gaU9F
} p8%qU>~+4
} n-"(~
//负责部分文件的抓取 k)S1Zs~G
**FileSplitterFetch.java 0 h!Du|?
*/ L#byYB;E{
package NetFox; v>B412l
__.MS6"N
A`f"<W-m
import java.io.*; 8TeOh1\
import java.net.*; F!ztU8,
u*)/e9C
\j62"
public class FileSplitterFetch extends Thread { 5 k3m"*
/u4RZ|&as
In96H`
String sURL; //File URL ;6[6~L%K}
long nStartPos; //File Snippet Start Position 8lYA6A
long nEndPos; //File Snippet End Position wPjq B{!Q
int nThreadID; //Thread's ID DMG~56cTO,
boolean bDownOver = false; //Downing is over /ta}12Z
boolean bStop = false; //Stop identical KxX[8
FileAccessI fileAccessI = null; //File Access interface yef\Y3X
_Ik?WA_;
bAZoi0LR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m]>zdP+
{ e!*]y&W
this.sURL = sURL; %(/E `
this.nStartPos = nStart; -?)^ hbr
this.nEndPos = nEnd; ',0:/jSz
nThreadID = id; m.Zy$SDj(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y2#>a8SRS
} /h+ W L
},l i'r#p
\j`0f=z_
public void run() y&,|+h
{ 'lA}E
while(nStartPos < nEndPos && !bStop) ZPG,o5`%
{ :.e'?a
qsep9z.
VRQ`-#
try{ WK`o3ayH-
URL url = new URL(sURL); ;kk[x8$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); & mOn]
httpConnection.setRequestProperty("User-Agent","NetFox"); b},2A'X
String sProperty = "bytes="+nStartPos+"-"; G^k'sgy.
httpConnection.setRequestProperty("RANGE",sProperty); 5+M,X kg
Utility.log(sProperty); s;OGb{H7
L?d?O
rz%~=Ca2j
InputStream input = httpConnection.getInputStream(); :C} I6v=
//logResponseHead(httpConnection); qS/}aDk&
j*?8w(!
5:IDl1f5
byte[] b = new byte[1024]; -eF-r=FR
int nRead; @c]KHWI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {S{%KkAV
{ HfVHjF)
nStartPos += fileAccessI.write(b,0,nRead); 7! >0
//if(nThreadID == 1) z!3=.D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qy"Jt]O
} &S{r;N5u
agx8*x
3)EJws!
Utility.log("Thread " + nThreadID + " is over!"); s`bGW1#io
bDownOver = true; 6~%><C
//nPos = fileAccessI.write (b,0,nRead); H_RfIX)X
} iN Oj@3x
catch(Exception e){e.printStackTrace ();} w<`0D)mQ
} I2$DlEke
} \ T#|<=
K`Kv.4
.8|wc
//打印回应的头信息 2~$S @c
public void logResponseHead(HttpURLConnection con) ),p0V
{ M/p9 I gp
for(int i=1;;i++) ?0/$RpFEM#
{ x!_5/
String header=con.getHeaderFieldKey(i); /&Oo)OB;
if(header!=null) l|WFS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i|1*bZ6'
Utility.log(header+" : "+con.getHeaderField(header)); %Z_O\zRqy)
else U_*,XLU
break; n>,:*5"G
} 'M~`IN`
} D0jV}oz
u?`{s88_mF
LsWD^JE.
public void splitterStop() w UxFE=ia
{ q* R}yt5
bStop = true; x8@ 4lxj
} \.mVLLtG
2]mV9B
<(jk}wa<
} 00 x-
n/5T{NfG
,<%uG6/",g
/* EN2t}rua
**FileAccess.java 4C3_gm
*//文件访问(定位，写) p$\>3\
package NetFox; ]oV{JR]
import java.io.*; b M1\z
|iHMAo
l%EvXdZuOy
public class FileAccessI implements Serializable{ AaYH(2m-
!ddyJJ^a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q[#}Oh6$
RandomAccessFile oSavedFile; ?0t^7HMP
long nPos; L=#NUNiXr
rgVRF44X{
P$U"y/
public FileAccessI() throws IOException H\QkU`b
{ Qz[^J
this("",0); /Ot3[B
} @G2# Z
zE/l
wvq4 P
public FileAccessI(String sName,long nPos) throws IOException X=#us7W}
{ _ACN
oSavedFile = new RandomAccessFile(sName,"rw"); 1jd{AqHl
this.nPos = nPos; VH]}{i"`
oSavedFile.seek(nPos); yIKpyyC9H
} _!o8s%9be
'w=|uE {^
!0@4*>n
public synchronized int write(byte[] b,int nStart,int nLen) :*KTpTa
{ )K{s^]Jp
int n = -1; )9`HO?
try{ Hnt*,C.0
oSavedFile.write(b,nStart,nLen); jXeE]A"
n = nLen; Csuasi3]1d
} vT EqT
catch(IOException e) 4 -tC=>>wc
{ 7zH2dqrj
e.printStackTrace (); [bHm-X]
} ~g=&wT11
*,Bm:F<m
T$lV+[7
return n; .+1I>L
} Z}$sY>E
|`:cB
62HA[cr&)
} {ze69 h
a5#G48'X
hP+4{F*}-
/* |s! _;6
**SiteInfoBean.java jM$bWtq2
*/ qt@/
package NetFox; O(W"QY
mzK0$y#*o
D-/6RVq0m
public class SiteInfoBean { ;F258/J
"BSY1?k{
IVh5SS
private String sSiteURL; //Site's URL /GGyM]k3
private String sFilePath; //Saved File's Path UH>~Y N
private String sFileName; //Saved File's Name 7_ix&oVI
private int nSplitter; //Count of Splited Downloading File z)C}}NH*!@
4uiq'-
i6V$mhL
public SiteInfoBean() 6#U~>r/
{//nSplitter的缺省值为5 ]!AS%D`
//default value of nSplitter is 5 iXm&\.%
this("","","",5); ~k&b
} I4N7wnBp
Jt5V{9:('
<=n;5hv:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bpBn3f`?*
{ Z(6.e8fK
sSiteURL= sURL; tAN!LI+w
sFilePath = sPath; c]Epg)E
sFileName = sName; f DXK<v)
this.nSplitter = nSpiltter; F)cCaE;
Hy3J2p9.
i$] :Y`3h
} @HbRfD/!
)L9eLxI
Trs~KcsD
public String getSSiteURL() E'\gd7t ;
{ *}89.kCBF
return sSiteURL; )(G<(eiD
} tlQ6>v'
YxM\qy{Vr
V5lUh#@TN&
public void setSSiteURL(String value) iO*5ClB
{ ywp_,j9F
sSiteURL = value; ,Sgo_bC/|
} d=bKNA90
Oz%6y ri
;t+p2i
public String getSFilePath() 6ZIPe~`
{ 01@WU1IN
return sFilePath; p?$N[-W6-
} YWn""8p;P
>!1]G"U
s;bGg
public void setSFilePath(String value) AHs%?5YTY;
{ ,mm97I
sFilePath = value; !LH;K
} lx2#C9L_
/4Wf\ Zu
$EY[CA E
public String getSFileName() R8[VD iM6E
{ 0 8L;u7u
return sFileName; ]@9W19=P!P
} q*lk9{>
P\Qvj7_
YMu#<ZG
public void setSFileName(String value) "&SE!3*m`I
{ vx?KenO}
sFileName = value; CfW#Wk:8J
} _XZK2Q[
q}Po)IUT`5
{BlTLAKm
public int getNSplitter() s7yKxg+`{
{ !y_L~81?
return nSplitter; )>h3IR
} &5K3AL
uH$hMg
gWHY7rv
public void setNSplitter(int nCount) =T3{!\tH
{ (QIU3EN
nSplitter = nCount; 4OM ]8I!
} G h+;Vrx
} ?M4ig_
$DH/
sRT5i9TQ
/* WY|~E%k
**Utility.java CX/[L)|Ru
*/ b(N+_= n
package NetFox; ;sA 5&a>!
Bs0~P 4^
i +@avoW
public class Utility { aW:*!d#
>AV9 K
3q/"4D
public Utility() l1zPL3"u_^
{ *H/)S5
NUnwf h
0* x?rO?
} pqs!kSJV
0UpRSh)#
//线程睡眠 +>1Yp">?
public static void sleep(int nSecond) x3'ANw6E
{ 2Ax(q&`9
try{ dKPXs-5
Thread.sleep(nSecond); "8a V~]~Dj
} SLP$|E;
catch(Exception e) J",Cwk\
{ >1Iw!SO+
e.printStackTrace (); t_I-6`8o]
} nZj&Ma7R
} pDP* 3
6$PQ$
//日志 OkQ< Sc
public static void log(String sMsg) ?_{{iil
{ TQt[he$O
System.err.println(sMsg); d^?e*USh
} |oeg'T
85"Szc-#
m6 M/G
public static void log(int sMsg) g#{7qmM
{ $n8&5<
System.err.println(sMsg); Dp*:oMATx0
} /FXb,)1t
} T^8`ji
De$Ic"Z9L
MIr[_
/* 0RdW.rZJ
**TestMethod.java ~]%re9jGW
*/ rr1,Ijh{D
package NetFox; ;YokPiBy
:[?7,/w
D@w&[IF
public class TestMethod { p&(z'd
mtFC H
meB9:w[m
public TestMethod() #?M[Q:
{ ///xx/weblogic60b2_win.exe p/ZgzHyF
try{ sn[<Lq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QWm g#2'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Rz>@G>b:
SiteFileFetch fileFetch = new SiteFileFetch(bean); p*$=EomY
fileFetch.start(); Rwj 3o
} 1N]-WCxQ
catch(Exception e){e.printStackTrace ();} )MN6\v
~EDO< O>3
`aMnTF5:
} !+hw8@A
/$qB&OWJn
0^P9)<k'
public static void main(String[] args) A@.ruG$
{ *Q [%r
new TestMethod(); t P'._0n0
} *Q-uE
} vO zUAi
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