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)); D:JS)+]
} /:p8I6;
for(int i=0;i<nEndPos.length-1;i++) :1;Q(9:v
{ X;!~<~@Y
nEndPos = nStartPos[i+1]; bfdVED
} p/*"4-S
nEndPos[nEndPos.length-1] = nFileLength; #epy%>
} p`P~i&_
} pbLGe'
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S GM!#K
//启动子线程 78]gtJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JJnYOau
for(int i=0;i<nStartPos.length;i++) P^i.La,
{ E\$C/}T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d#>y}H9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &z@~B&O
nStartPos,nEndPos,i); nIBFk?)6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >qh?L#Fk
fileSplitterFetch.start(); ]tY:,Mfs
} Cv^`&\[SW+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;`UecLb#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Yb:pAzw6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :(p)1=I
nEndPos = " + nFileLength); Lgi[u"Du
// fileSplitterFetch[nPos.length-1].start(); _~M^ uW^l
kg>>D
o@k84+tn(
//等待子线程结束 h{_*oBa
//int count = 0; 0m)&YFZ[(
//是否结束while循环 4l @)K9F
boolean breakWhile = false; f$F*3
'Cc(3
sbS~N*{E
while(!bStop) ROdK8*jL
{ ZnfNQl[
write_nPos(); v>mn/a
Utility.sleep(500); NXU`wnVJ
breakWhile = true; aE/D*.0NI
*e/K:k
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for(int i=0;i<nStartPos.length;i++) BX< dSK
{ AGq>=avv
if(!fileSplitterFetch.bDownOver) ]KuMz p!
{ ]'h; {;ug
breakWhile = false; J/W{/E>;
break; RU&_j*U
} _Qd,VE 8u
} FxRXPt FK
if(breakWhile) "A[ b rG
break; |d}MxS`^
UtJa3ya
`78V%\
//count++; S$[k Q|Am
//if(count>4) 0rE(p2
// siteStop(); rU2iy"L
} YQ]\uT>}&
lA;a
ll<NIdf\r
System.err.println("文件下载结束！"); M1!pQC_9
} \Fb| {6+
catch(Exception e){e.printStackTrace ();} Qe$k3!
} %b}gDWs
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uk7'K 0j
//获得文件长度 m*e YC
public long getFileSize() ^^Jnv{)
{ EKZVF`L
int nFileLength = -1; A6"Hk0Hf
try{ ]%dnKP~
URL url = new URL(siteInfoBean.getSSiteURL()); :}q\tNY<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \a|L/9%
httpConnection.setRequestProperty("User-Agent","NetFox"); ,k0r
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int responseCode=httpConnection.getResponseCode(); +R.N%_
if(responseCode>=400) p{Sh F.
{ <{J5W6
processErrorCode(responseCode); " I+p
return -2; //-2 represent access is error ofdZ1F
} 6}dR$*=
p>*i$
P?ep]
String sHeader; +K$NAT
C)RBkcb
*"{&FEV
for(int i=1;;i++) x?yD=Mq_
{ acW'$@y9?N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G^Tk 20*
//Utility.log(in.readLine()); C"w {\ &R
sHeader=httpConnection.getHeaderFieldKey(i); Ru\_dr2yI}
if(sHeader!=null) 1np^(['ih
{ U4,2br>
if(sHeader.equals("Content-Length")) m7qqY
{ }5 9U}@xC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yL1bS|@
break; Bl;KOR
} C+V* Fh3
} t+TYb#Tc
else `\Unpp\I
break; 0pgY1i7
} 53OJ-m%a
} Y)I8eU{Wl(
catch(IOException e){e.printStackTrace ();} KeBQH8A1N
catch(Exception e){e.printStackTrace ();} *nTU#U
-9Ws=r0R
USPTpjt8R
Utility.log(nFileLength); ANMg
~H6;I$e[
\h{r;#g
return nFileLength; G*}F5.>8(
} saZ>?Owz
j tA*pL'/V
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//保存下载信息（文件指针位置） ?.bnIwQe
private void write_nPos() HgRwiIt
{ ;</Lf=+Vm
try{ F?4(5 K
output = new DataOutputStream(new FileOutputStream(tmpFile)); kCP$I732
output.writeInt(nStartPos.length); m <k!^jp
for(int i=0;i<nStartPos.length;i++) H{G{H=K_
{ ]B4}eBt5)@
// output.writeLong(nPos); b"j|Bb
output.writeLong(fileSplitterFetch.nStartPos); #=,(JmQPt
output.writeLong(fileSplitterFetch.nEndPos); GG6%bF
} edC4BHE
output.close(); S"2qJ!.u
} +8P,s[0<R_
catch(IOException e){e.printStackTrace ();} w YNloU
catch(Exception e){e.printStackTrace ();} ((3}LQ
} 6XV<? 9q
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pa]"iZz
//读取保存的下载信息（文件指针位置） #gbH^a'
private void read_nPos() 2y GOzc
{ i%{X9!*%TX
try{ y=sGe!^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f@V3\Z/6E
int nCount = input.readInt(); a}nbo4jK
nStartPos = new long[nCount]; 3smM,fi
nEndPos = new long[nCount]; ":;@Hnb/
for(int i=0;i<nStartPos.length;i++) "4xfrlOc
{ P9Q2gVGAO{
nStartPos = input.readLong(); tbDoP Y
nEndPos = input.readLong(); I4_d[O9
} lX!`zy{3k
input.close(); 6j9)/HP
} =[tSd)D,y
catch(IOException e){e.printStackTrace ();} 2 h|e
catch(Exception e){e.printStackTrace ();} H=MCjh&$q
} H#d:kilNy
i8pU|VpA
}=}>9DSM
private void processErrorCode(int nErrorCode) b\55,La
{ Jobiq]|>
System.err.println("Error Code : " + nErrorCode); L\aBc}
} v:_B kHN'
MBr:?PE7
pd@;b5T
//停止文件下载 *TdnB'Gd
public void siteStop() <9A@`_';Aq
{ Ka_S n
bStop = true; ]Uc`J8p,
for(int i=0;i<nStartPos.length;i++) S01wwZ
fileSplitterFetch.splitterStop(); \+PIe7f_
BN_7Ay/k
5i So8*9}
} %"$@%"8;3
} Yxd X#3
//负责部分文件的抓取 -p,x&h,p
**FileSplitterFetch.java b'@we0V@S
*/ C*6S@4k
package NetFox; IO$z%r7
./-JbW
}ynT2a#LU'
import java.io.*; J{"kw1Lu
import java.net.*; b!>\2DlyJ
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public class FileSplitterFetch extends Thread { 2ef;NC.&n
ik,lSTBD
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String sURL; //File URL ]gb=
long nStartPos; //File Snippet Start Position S[:xqzyDg
long nEndPos; //File Snippet End Position ;&;W T
int nThreadID; //Thread's ID Ze^jG-SL$9
boolean bDownOver = false; //Downing is over q }C+tn"\
boolean bStop = false; //Stop identical rw%l*xgX
FileAccessI fileAccessI = null; //File Access interface !$qKb_#nC
i, nD5@#
]rBM5~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException VDEv>u4
{ }OShT+xeX
this.sURL = sURL; j8,n7!G
this.nStartPos = nStart; >um!Eo
this.nEndPos = nEnd; `(4pu6uT
nThreadID = id; XR+3j/zEQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +FFG#6e
} <&!]K?Q9i
lT8\}hNI+
ni CE\B~
public void run() 4g _"ku
{ ^C^*,V3
while(nStartPos < nEndPos && !bStop) 'C+;r?1!h
{ *e"a0
cd@.zg'sYn
@]CF&: P A
try{ jk~:\8M(A
URL url = new URL(sURL); Fw4*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8Z#j7)G
httpConnection.setRequestProperty("User-Agent","NetFox"); eARk QV
String sProperty = "bytes="+nStartPos+"-"; ?h\mk0[
httpConnection.setRequestProperty("RANGE",sProperty); MFit|C
Utility.log(sProperty); ;^k7zNf-
S9sR#
OJ>.-"
InputStream input = httpConnection.getInputStream(); 0Ce]V,i6C>
//logResponseHead(httpConnection); ik1tidw
&R-H"kK?
h5%|meZQb
byte[] b = new byte[1024]; B33$ u3d
int nRead; *tQk;'/A]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WPuz]Ty
{ wNCCH55Pt
nStartPos += fileAccessI.write(b,0,nRead); v@ C,RP9
//if(nThreadID == 1) 7()?C}Ni-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gz#4{iT~
} L-i>R:N4
]5CNk+`'
>%b\yl%0
Utility.log("Thread " + nThreadID + " is over!"); SqPtWEq@P
bDownOver = true; B~WtZ-%%E
//nPos = fileAccessI.write (b,0,nRead); <_S@6?
} QOFvsJ<s
catch(Exception e){e.printStackTrace ();} H:&?ha,9
} >O`l8tM
} eBW=^B"y+
Jcf"#u-Q/
P8yIegPY
//打印回应的头信息 8}p8r|d!ls
public void logResponseHead(HttpURLConnection con) <EX7WA
{ |(IO=V4P
for(int i=1;;i++) $r.U
{ [2Mbk~
String header=con.getHeaderFieldKey(i); 1hQN8!:<
if(header!=null) oW}!vf3z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T`YwJ6N
Utility.log(header+" : "+con.getHeaderField(header)); ]TpU"JD
else U\<-mXv
break; N_wp{4 0/
} ks(SjEF
} Ws[D{dS/
a=}*mF[ug
wGKo.lt
public void splitterStop() 'A{h iY
{ *MM#Z?mP
bStop = true; >=,uau7
} F#r#}.B='U
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`x8Bn"
} 8QgA@y"
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%|Qw9sbd
/* rs8\)\z
**FileAccess.java B&KL2&Z~Pq
*//文件访问(定位，写) {ShgJ;! Q
package NetFox; mB55PYA
import java.io.*; 3Kq`<B~%
\{|ImCH
cgZaPw2 bw
public class FileAccessI implements Serializable{ !rL<5L
kEN#u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %CH6lY=lI
RandomAccessFile oSavedFile; ]?l{j
long nPos; O12Q8Oj!0
@"87F{!
*YV S|6bs
public FileAccessI() throws IOException fv'4f$U
{ 0irr7Y
this("",0); 4*H"Z(HP
} >%%=0!,yX
X T>('qy
*> 3Qd7
public FileAccessI(String sName,long nPos) throws IOException Opg#*w%-
{ [=M%
oSavedFile = new RandomAccessFile(sName,"rw"); |7F*MP
this.nPos = nPos; K'b*A$5o
oSavedFile.seek(nPos); L4'[XcY
} L10IF
%_)zWlN
i.a _C'<$
public synchronized int write(byte[] b,int nStart,int nLen) 7nE"F!d+0
{ `u'dh{,gE
int n = -1; pa/9F[
try{ #gZ|T M/h
oSavedFile.write(b,nStart,nLen); ~9M!)\~
n = nLen; ;IP~Tb]&
} D!3{gV#
catch(IOException e) v548ysE)
{ "~+.Af
e.printStackTrace (); )C]x?R([m
} <e"J4gZf&
z/|BH^Vw
w9&#~k]5
return n; wq0aF"k
} N+Sq}hI
s;.=5wcvi?
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} $Xf(^K
G2Qjoe`Uc
DZ`k[Z.VZ
/* =Viy^ieN$
**SiteInfoBean.java " ~Q*XN2
*/ d0UZ+ RR#
package NetFox; knHv?#
[#b2%G1
v<h;Di@
public class SiteInfoBean { %$X\"
HYClm|
i57( $1.
private String sSiteURL; //Site's URL y?:dE.5p|
private String sFilePath; //Saved File's Path YMzBAf
private String sFileName; //Saved File's Name Go8F5a@j
private int nSplitter; //Count of Splited Downloading File BQrL7y
H!eh J$[
-Zy)5NB-tZ
public SiteInfoBean() o:\XRPB
{//nSplitter的缺省值为5 x-Z^Q C
//default value of nSplitter is 5 Lo`F
this("","","",5); 4M`Xrfwm'[
} `iYc<N`
:t$A8+A+0
{8CWWfHCD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zy)i1d
{ _wu*M
sSiteURL= sURL; P[i\e7mR
sFilePath = sPath; 2P}I'4C-
sFileName = sName; f1cl';
this.nSplitter = nSpiltter; SGf9U^ds
Q<=Y
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} :JV\){P
.h8M
UxqWnHH.`
public String getSSiteURL() Q1V2pP+=@
{ /~hbOs/ L
return sSiteURL; ]Z@k|Nw
} ixI:@#5wY
@YZ 4AC
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public void setSSiteURL(String value) +TX/g~
{ "iek,Y}j7
sSiteURL = value; j%xBo:
} Bw-s6MS
K2|7%
&oN/_7y
public String getSFilePath() fM":f| G
{ <Jwo?[a
return sFilePath; L8P36]>
} #v/ry)2Y=
l>Av5g)
>d%VDjk .
public void setSFilePath(String value) Gpu_=9vzv
{ _Ex?Xk
sFilePath = value; ] 09yy
} DTy/jaK
M&e8zS
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public String getSFileName() q$>_WF#||
{ 1n3$V:00
return sFileName; ~e^)q>Lb7(
} `o-*Tr
6\`DlUn'*
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public void setSFileName(String value) }su6izx
{ s=/^lOOO
sFileName = value; rw*M&qg!z
} t-EV h~D1p
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-tP.S1D
public int getNSplitter() |[WL2<
{ Q X):T#^V
return nSplitter; V.j#E1P
} FO^24p
?*o;o?5s^
LDX y}hm)
public void setNSplitter(int nCount) ?N_)>&b
{ T{HfP
nSplitter = nCount; Oga1u
} }200g_^
} #M:B3C!ouY
1^sbT[%R
I~k=3,7<
/* yk#rd~2Z0
**Utility.java ~2 Oc K
*/ sD2Qm
package NetFox; sH@ &*
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public class Utility { B$`d&7I;D
@>Ek'~m
_UIgRkl.
public Utility() kPedX
{ ZIy(<0
d~/xGB`<
o@',YF>OQ
} H<z30r/-w
QpJIDM/
//线程睡眠 ChVY Vx(
public static void sleep(int nSecond) i6A$1(:h
{ c}'Xoc
try{ 8xgc[#
Thread.sleep(nSecond); !xH,y
} n4R]+&*
catch(Exception e) b<\GI7
{ M;PlSb
e.printStackTrace (); ~QO< B2hS}
} Ks51:M
} 'Ye]eL,I\
F]0Jwm{
//日志 WS5"!vz
public static void log(String sMsg) ^@Y9!G=
{ &gJW6<
System.err.println(sMsg); 6ku8`WyoF
} d}pGeU'
d4V 2[TX
"d:.*2Z2
public static void log(int sMsg) P 4H*jy@?
{ `43vxcMg
System.err.println(sMsg); uzO{{S-
} % dYI5U89
} bsMC#xT
|&(H^<+Xp
o KlF5I
/* Qw}xGlF,
**TestMethod.java ko>M&/^
*/ E4hq}
package NetFox; XWc|[>iO
69-$Wn43<
y^, "gD
public class TestMethod { dZ-Ny_@&
EO"=\C,
Px$'(eMj^3
public TestMethod() ud.poh~|
{ ///xx/weblogic60b2_win.exe ItMl4P`|
try{ .^BWR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y0rf9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fo*!a$)
SiteFileFetch fileFetch = new SiteFileFetch(bean); LuLy6]6D;
fileFetch.start(); Fz{o-4
} 2-p8rGI_F
catch(Exception e){e.printStackTrace ();} .5Q5\qc=
x}uwWfe3
E=A/4p6\$
} ~xP Szf
l#mtND3
]}5`7
public static void main(String[] args) Q-:Ah:/
{ _AVy:~/
new TestMethod(); y B1W>s8&
} Cx$9#3\
} BzN/6VEw
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