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)); +UN<Zp7I/
} ,3i,P(?(
for(int i=0;i<nEndPos.length-1;i++) Y.#:HRtgW
{ p,g1eb|E
nEndPos = nStartPos[i+1]; ^L4Qbc(vJ
} a,t``'c;
nEndPos[nEndPos.length-1] = nFileLength; bvBHYf:^
} wN-i?Ek0;
} nz.{P@[Qk
^D^JzEy'?C
revF;l6->C
//启动子线程 %^.%OCX:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yL4 T
for(int i=0;i<nStartPos.length;i++) |R/.r_x,V?
{ d)o!5L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ck =;1sGh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B$Z3+$hfF
nStartPos,nEndPos,i); P,DC7\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T'-FV
fileSplitterFetch.start(); "t=hzn"~%
} Joe_PS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :G w~7v_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >ydRSr^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hg@}@Wq\)
nEndPos = " + nFileLength); 3voT^o
// fileSplitterFetch[nPos.length-1].start(); d&8APe
tMx}*l|]
Q;Wj?8}
//等待子线程结束 [Qt?W gPj
//int count = 0; #L}+H!Myh
//是否结束while循环 V D?*h
boolean breakWhile = false; Uh1NO&i.W
?']h%'Q
F1%vtk;2?
while(!bStop) =QJRMF
{ DaHZ{T8>d
write_nPos(); -D^A:}$
Utility.sleep(500); J<gJc*Q
breakWhile = true; 98jN)Nl,oD
)2q~u%9n
x"P);su
for(int i=0;i<nStartPos.length;i++) \vfBrN
{ gwd (N
if(!fileSplitterFetch.bDownOver) nP~({:l8X
{ `IpA.| Y
breakWhile = false; IxR?'
break; 1'v5/
} =VLS/\A
} {Hmo1|_S|
if(breakWhile) yqXH:757~
break; \'CN
DmVP
GV6K/T:
//count++; 3l<S}k@M)
//if(count>4) pg+[y<B
// siteStop(); wu9=N ^x
} o'<^LYSnB
*1Z5+uVT[
~9\WFF/
System.err.println("文件下载结束！"); S\6[EQ65
} i|)Su4Dw
catch(Exception e){e.printStackTrace ();} 6&Juv
} 5m:i6,4
RyB~Lm`ZK%
X;F?:Iw\
//获得文件长度 dUznxZB
public long getFileSize() V}o n|A
{ 39F Of
int nFileLength = -1; ^taBG3P
try{ OU4pjiLx
URL url = new URL(siteInfoBean.getSSiteURL()); ,vqr<H9e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d1@%W;qX!
httpConnection.setRequestProperty("User-Agent","NetFox"); v4miU;|\
EVX{ 7%
vKwQXR~C
int responseCode=httpConnection.getResponseCode(); =$8nUX`
if(responseCode>=400) wv QMnE8\
{ Xd E`d.
processErrorCode(responseCode); r,goRK.
return -2; //-2 represent access is error Hd7,ZHj3^
} I2$T"K:eo
$GQ`clj<
_sE#)@p
String sHeader; @;xMs8@
yL^UE=#C_
LLWB
for(int i=1;;i++) C'=k&#<-
{ &0TVi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +bK.NcS
//Utility.log(in.readLine()); rKHY?{!
sHeader=httpConnection.getHeaderFieldKey(i); cH-@V<
if(sHeader!=null) 'Djm0
{ ~1m2#>
if(sHeader.equals("Content-Length")) b?4/#&z]
{ e6X[vc|Y}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XS0xLt=
break; O<)y-nx;X
} ``,k5!a66\
} ^[Ua46/"m
else ._wkj
break; 9%ii '{
} O?8Ni=]
} &~UJf4b|A
catch(IOException e){e.printStackTrace ();} 8;y&Pb~)
catch(Exception e){e.printStackTrace ();} p2J|Hl|
G1t\Q-|l0
N$Y" c*
Utility.log(nFileLength); wi8Yl1p]!z
[>#*B9
HIGq%m=-x
return nFileLength; ]Mj/&b>"e
} sG~<M"znV
[U#72+K
-IlJ^Al4
//保存下载信息（文件指针位置） "'^4*o9
private void write_nPos() kVI#(uO
{ n\I#CH0V
try{ 7@.cOB`y@3
output = new DataOutputStream(new FileOutputStream(tmpFile)); }7{t^>;D
output.writeInt(nStartPos.length); H4OhIxK
for(int i=0;i<nStartPos.length;i++) T9 <2A1
{ ,U*)2`[
// output.writeLong(nPos); :RSz4
output.writeLong(fileSplitterFetch.nStartPos); \^1+U JU
output.writeLong(fileSplitterFetch.nEndPos); zPEg
} krq/7|
output.close(); sfr(/mp(
} 'B83m#HR#
catch(IOException e){e.printStackTrace ();} 3:"]Rn([P
catch(Exception e){e.printStackTrace ();} #tt?!\8C
} TGuiNobD
t3Z_Dp~\
b1pQ`qt
//读取保存的下载信息（文件指针位置） S1n3(U:m
private void read_nPos() 6#}93Dgv4
{ ` b !5^W
try{ +^rh[>W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ERUt'1F?]
int nCount = input.readInt(); Nf+b"&Zh`
nStartPos = new long[nCount]; 0.r4f'vk
nEndPos = new long[nCount]; f:zFFpP.j@
for(int i=0;i<nStartPos.length;i++) 7;.xc{
{ Bhqft;Nuh
nStartPos = input.readLong(); X.ONa_
nEndPos = input.readLong(); QQk{\PV
} :J}t&t
input.close(); \&V0vN1
} [=uo1%
catch(IOException e){e.printStackTrace ();} zJa)*N
catch(Exception e){e.printStackTrace ();} %zC[KE*~
} ?%Rw(E
F Kc;W
2y0J`!/)
private void processErrorCode(int nErrorCode) kH*Pn'
{ zWw2V}U!
System.err.println("Error Code : " + nErrorCode); aYL|@R5;e
} 6Dws,_UAZ4
RO\gax
"`}~~.q
//停止文件下载 QVZD/shq
public void siteStop() 7Y=cn_ wU
{ r#WT`pav
bStop = true; k.h`Cji@
for(int i=0;i<nStartPos.length;i++) 78n=nHS
fileSplitterFetch.splitterStop(); IWVlrGyM
< (RC|?
"_L?2ta
} W]<$0
} ?wMHS4
//负责部分文件的抓取 kI*(V[i
**FileSplitterFetch.java Xog/O i
*/ hovGQHg
package NetFox; :/YO ni1h
G@!z$
y$Zj?Dd#
import java.io.*; sK$wN4k
import java.net.*; mIZwAKo
VvByHcLv
u#W5`sl
public class FileSplitterFetch extends Thread { 71FeDpe
\a"Ct'
GYRYbiwqdi
String sURL; //File URL ?{o/I\\
long nStartPos; //File Snippet Start Position [}nK"4T"Ri
long nEndPos; //File Snippet End Position {hSGv
int nThreadID; //Thread's ID Gtv,Izt
boolean bDownOver = false; //Downing is over >(9F
boolean bStop = false; //Stop identical v=YK8fNi
FileAccessI fileAccessI = null; //File Access interface 5`^o1nGO'
[c K^+s)N
U3;aLQ*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I"L;L?\S
{ }`/gX=91
this.sURL = sURL; #~:P}<h
this.nStartPos = nStart; V|Tud
this.nEndPos = nEnd; BJjx|VA+
nThreadID = id; W@L3+4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8$P>wCK\l
} 33l>{(y
KV!<Oq
YZ#V#[j'^
public void run() db=$zIB[:
{ 9pWy"h$H
while(nStartPos < nEndPos && !bStop) 0V,Nv9!S
{ <~Qi67I
MKGS`X]<J
UgHf*m
try{ $FM' 3%B[
URL url = new URL(sURL); HP2wtN{Zs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E+_&HG}a
httpConnection.setRequestProperty("User-Agent","NetFox"); 8Vl!|\x5
String sProperty = "bytes="+nStartPos+"-"; $j` $[tX6l
httpConnection.setRequestProperty("RANGE",sProperty); Aw^yH+ae
Utility.log(sProperty); ZwI 1* f
#5CI)4x0!
A;K(J4y*
InputStream input = httpConnection.getInputStream(); >O{7/)gS^
//logResponseHead(httpConnection); 8m=Z|"H@
F%.xuLW
HB& &
byte[] b = new byte[1024]; uF(k[[qaiN
int nRead; g#^|oYuH6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I@7/jUO
{ M8W#io
nStartPos += fileAccessI.write(b,0,nRead); wvc>0?t'
//if(nThreadID == 1) -/{af
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,TC~~EWq
} t\y-T$\\
E{^^^"z P
_g|acBF
Utility.log("Thread " + nThreadID + " is over!"); h* .w"JO
bDownOver = true; ;_JH:}j
//nPos = fileAccessI.write (b,0,nRead); s${_K*g6
} OD9 yxN>P
catch(Exception e){e.printStackTrace ();} 4rB8Nm1
} e1 a*'T$z
} +cg {[f,J;
D5A=,\uk
hY;_/!_
//打印回应的头信息 r2eQ{u{nX
public void logResponseHead(HttpURLConnection con) PnWD}'0V
{ bkQ3c-C<
for(int i=1;;i++) pG yRX_;
{ }C6@c1myq-
String header=con.getHeaderFieldKey(i); Q7Ij4
if(header!=null) c?6d2jH.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q_P5MLU>
Utility.log(header+" : "+con.getHeaderField(header)); (aKZ5>>cN
else `F1dyf!p<
break; oh\,OW
} -CBD|fo[h
} !oMt_k X
uEd,rEB>
jXIEp01
public void splitterStop() =HE m)
{ &4kM8Qh
bStop = true; R2^iSl%pj
} k/`i6%F#m
pCt}66k}
m^tNqJs8
} ~mH+DV3
31XU7A
olty4kGD$V
/* S<oQ}+4[~
**FileAccess.java iHz[Zw^.s
*//文件访问(定位，写) hx!`F
package NetFox; Nlt4)
import java.io.*; "{F;M{h$},
.hN3`>*V
!<Z{@7oH
public class FileAccessI implements Serializable{ YNM\pX'
8~5|KO >F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S}gD,7@
RandomAccessFile oSavedFile; 3?ba 1F0Nw
long nPos; G[6=u|(M
60PYCqWc
BX$hAQ(6Q
public FileAccessI() throws IOException |R~;&x:
{ *i?.y*g
this("",0); 6FjVmje
} q<XcOc5
7Po/_%
s/S+ ec3
public FileAccessI(String sName,long nPos) throws IOException D8/sz`N7Q
{ 4A~)b"j5
oSavedFile = new RandomAccessFile(sName,"rw"); T46{*(
this.nPos = nPos; f[@#7,2~M
oSavedFile.seek(nPos); :&$Xe1)i]
} "jGe^+9uT
? ).(fP
MZ^Ch
public synchronized int write(byte[] b,int nStart,int nLen) E& ]_U$
{ ^ wQcB
int n = -1; r5)f82pQ
try{ A_Gp&acs$
oSavedFile.write(b,nStart,nLen); =g2\CIlVU6
n = nLen; CjZ6NAHc
} Kq6qXc\x
catch(IOException e) AIfk"2
{ M,{<TpCx
e.printStackTrace (); 6QptKXu7
} EG1x
s}!"a8hU`
*2:Yf7rvI+
return n; *]9XDc]{j1
} w{ m#Yt
4H9xO[iM
Kz^hQd
} h>Rpb#]
)fR1n}#
UJs?9]x>
/* j)@oRWL<
**SiteInfoBean.java 0C7"3l
*/ +}]wLM}\UF
package NetFox; @}{VM)Fc+
I)uASfT$
Y;PDZbK3
public class SiteInfoBean { `R ]&F$i(E
B)d@RAk
9;:7e*x]lc
private String sSiteURL; //Site's URL A>y#}^l]
private String sFilePath; //Saved File's Path Oi#k:vq4
private String sFileName; //Saved File's Name lc-*8eS
private int nSplitter; //Count of Splited Downloading File fa.f(c
L%4tw5*N
C$0ITw
public SiteInfoBean() .?7So3
{//nSplitter的缺省值为5 h@/>?Va
//default value of nSplitter is 5 LQ|<3]
this("","","",5); Ae3#>[]{
} n]Ebwznt-
-*5yY#fw}
C890+(D~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @) ]t8(
{ n7'<3t
sSiteURL= sURL; |O^V)bZmx
sFilePath = sPath; pe|\'<>i
sFileName = sName; akY6D]M
this.nSplitter = nSpiltter; -hm9sNox
t"FRLC
}8X:?S %
} +0)5H>h
{S# 5g2
OQ 0b$qw
public String getSSiteURL() $M%}Oz3*
{ 2}1!WIin
return sSiteURL; |oB]6VS`
} [kQ"6wh8
HJ(=?TU
|O'Hh7
public void setSSiteURL(String value) ec,z6v^9
{ yA457'R1
sSiteURL = value; @#J H=-06
} Y-?51g[u
;2 \<M6
gS0,')w
public String getSFilePath() NdaM9a#TZ
{ m}sh I8S
return sFilePath; +._f.BRmX.
} $::51#^Wg
y0lLFe~
SlM>";C\
public void setSFilePath(String value) :1%VZvWk*
{ puk4D
sFilePath = value; _LLW{^V
} *YMXiYJR
YlxUx
VN1#8{
public String getSFileName() LH1BZ(5g
{ +X{cN5Y K
return sFileName; +lW+H12
} iOE9FW|e
.kz(V5
(p}9^Y
public void setSFileName(String value) :a#|
{ #zh6=.,7
sFileName = value; GXGN;,7EV
} dICnB:SSB
)I^)*(}
zV9 =
public int getNSplitter() Ji)%Y5F
{ P DNt4=C
return nSplitter; vWZ>Hf]`L
} _ +u sn.
1KNkl,E
|Sy}d[VKsZ
public void setNSplitter(int nCount) +<vqkc
{ )@?Qt2
nSplitter = nCount; bUpmU/RW
} f4qS OVv
} w`w `q'
\f~u85
?^F*"+qI
/* 'lSnyW{
**Utility.java %>oT7|x
*/ U<#$w{d:
package NetFox; hA$c.jJr.Z
Vw6>:l<+<
y?rK5Yos
public class Utility { T(t <Ay?c
[0( E>vm
{3_Ffsg`
public Utility() j@!BOL~?
{ c9>8IW
E0WrpGZ
uk>q\j
} KR+aY.
4C2>0O<^s
//线程睡眠 6Vu}kK)
public static void sleep(int nSecond) hv_pb#1Ks
{ g%KGF)+H
try{ 5G dY7t_1
Thread.sleep(nSecond); t\E-6u
} @p?b"?QaB
catch(Exception e) 3(XHF3q
{ [v>Z(
e.printStackTrace (); Al;%u0]5
} Q)7L^
} {g23[$X]N
I{Y {
//日志 kM}ic(K
public static void log(String sMsg) Z:r$;`K/
{ kfG65aa>_
System.err.println(sMsg); N23+1h
} B[2h
I=3B 5u
".Q!8j"@f
public static void log(int sMsg) 'IqK M
{ (PE8H~d
System.err.println(sMsg); d[qEP6B
} %s&E-*X
} &,6y(-
t8a@L(J$
UH.}B3H
/* @pEO@bbg>
**TestMethod.java EzeDShN=J
*/ 9cx!N,R t
package NetFox; GwU>o:g"
vb80J<4
d%[`=fs]|m
public class TestMethod { n+A'XBHk
!EyGJa[i
8M(|{~~3:
public TestMethod() is_dPc
{ ///xx/weblogic60b2_win.exe Q'%5"&XFD
try{ Ot8S'cB1,$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %o_0M^3W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CzDR%vx
SiteFileFetch fileFetch = new SiteFileFetch(bean); V+@%(x@D_
fileFetch.start(); 6=`m
} kxKnmB#m-
catch(Exception e){e.printStackTrace ();} ytcG6WN3
Ty,)mx){)
_|5FrN
} ~_^o?NE,
Yqz[sz5+m
Z2pN<S{5
public static void main(String[] args) \w@_(4")Qb
{ Rs(CrB/M
new TestMethod(); H--*[3".
} #|*,zIYo
} Qi'WV9ke
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