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)); Aaq%'07ihW
} I=<Qpd4
for(int i=0;i<nEndPos.length-1;i++) i '*!c
{ n^hkH1vY
nEndPos = nStartPos[i+1]; >1Hv c7DP
} 8zlvzp
nEndPos[nEndPos.length-1] = nFileLength; Z}>F V~4
} _(8#
} Yk?q\1
B&B:P
DQP!e6Of
//启动子线程 WSxoGly
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; srAWet
for(int i=0;i<nStartPos.length;i++) ~TS!5Wiv
{ ITqAy1m@C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y*\h?p[,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8IxIW0
nStartPos,nEndPos,i); ~xsJML
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "JLE
fileSplitterFetch.start(); <Lxp t
} w{xa@Q]t-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oe|;>0yf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jIrfJ*z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $':5uU1}
nEndPos = " + nFileLength); T|D^kL%m!
// fileSplitterFetch[nPos.length-1].start(); ty"L&$bf
Z4As'al
rEC
//等待子线程结束 00dY?d{[D
//int count = 0; ]cS(2hP7
//是否结束while循环 4;AQ12<[1
boolean breakWhile = false; O< /b]<[
kBrA ?
h^Yh~84T
while(!bStop) se2Y:v
{ {6RA~
write_nPos(); _a& Z$2O
Utility.sleep(500); *n&Sd~Mg
breakWhile = true; PI`Y%!P
|gu@b~8
_b-g^#L%
for(int i=0;i<nStartPos.length;i++) W'"?5} (
{ )uo".n|n~B
if(!fileSplitterFetch.bDownOver) (}>)X]
{ x4wTQ$*1
breakWhile = false; wEX<[#a-
break; o -)[{o\
} %$Py@g
} G!I5Er0pdy
if(breakWhile) G7+{O7
break; z;?jKE p
=>3,]hnep
gzSm=6Qw0
//count++; +6jGU'}[
//if(count>4) p!=8Pq.
// siteStop(); t1mG]
} tx9%.)M:n
tKLeq(
HpIi-Es7C
System.err.println("文件下载结束！"); ILH[q>
} 8N9,HNBT$
catch(Exception e){e.printStackTrace ();} mk!8>XvM
} w42{)S"
0n`Temb/
sH2xkUp
//获得文件长度 Hf_ pe
public long getFileSize() sn^ 3xAF
{ 85[ 7lO)[
int nFileLength = -1; ~Y*.cGA
try{ Ank_;jo
URL url = new URL(siteInfoBean.getSSiteURL()); c7@/<*E+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kv2o.q
httpConnection.setRequestProperty("User-Agent","NetFox"); {fl[BX]kZ
\I4Uj.'>\
1D8S}=5&
int responseCode=httpConnection.getResponseCode(); CPcUB4a%#
if(responseCode>=400) %@)q=*=y
{ ~'0n ]Fw
processErrorCode(responseCode); }b}jw.2Wu
return -2; //-2 represent access is error \_R<Q?D+
} 4]0:zS*O
SC2LY
-#/DK
String sHeader; ]:?S}DRG
$E^sA|KcT
Q{uO/6
for(int i=1;;i++) -]u>kjiIT
{ GIpYx`mHi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y&8`NS#_p?
//Utility.log(in.readLine()); -@#],s7
sHeader=httpConnection.getHeaderFieldKey(i); <kwF<J
if(sHeader!=null) v<2,OcH
{ V?x&\<;,
if(sHeader.equals("Content-Length")) E)jd>"
{ Bd=K40Z:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (,+#H]L
break; $t"QLsk0
} +N+117m
} *& );-r`.
else Sw-2vnSdM
break; Z>Rshtg
} %Y'/_ esH2
} q8/k$5E
catch(IOException e){e.printStackTrace ();} t4:/qy
catch(Exception e){e.printStackTrace ();} "oZ_1qi<
=X[?d/[
KV&6v`K/N
Utility.log(nFileLength); F 8sOc&L
Wrp+B[{r\
r]D>p&4
return nFileLength; d`$w3Hy
} +cmi?~KS*
}.9a!/@Aj
\vV]fX
//保存下载信息（文件指针位置） zIS ,N '
private void write_nPos() xnWezO_
{ w^nA/=;r
try{ `VGw5o
output = new DataOutputStream(new FileOutputStream(tmpFile)); z%+rI
output.writeInt(nStartPos.length); [U^Cz{G
for(int i=0;i<nStartPos.length;i++) g;AW
{ b|kL*{;
// output.writeLong(nPos); `uusUw-Gf
output.writeLong(fileSplitterFetch.nStartPos); i-4L{T\K
output.writeLong(fileSplitterFetch.nEndPos); 2MYez>D
} lAC"7 Z?F
output.close(); eA?|X|
} T7/DH
catch(IOException e){e.printStackTrace ();} eA Fp<2g
catch(Exception e){e.printStackTrace ();} x]%,?Vd?
} Gkfzb>_V]
\k=%G_W
Oz]$zRu/0
//读取保存的下载信息（文件指针位置） +CSR!
private void read_nPos() .Sa=VC?EZ
{ 0Db=/sJ>
try{ R!X+-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gCkR$.-E
int nCount = input.readInt(); &%/T4$'+Y+
nStartPos = new long[nCount]; O6b+eS
nEndPos = new long[nCount]; ?/sn"~"
for(int i=0;i<nStartPos.length;i++) >zfx2wh\a
{ })(robBkA
nStartPos = input.readLong(); !-%%94Q
nEndPos = input.readLong(); *nHMQ/uf
} 152s<lu1Z
input.close(); lm&^`Bn)
} gy|o#&e]%
catch(IOException e){e.printStackTrace ();} s)-bOZi
catch(Exception e){e.printStackTrace ();} 7u:kR;wk
} 0xCe6{86
3N2d@R
DOkuT/+
private void processErrorCode(int nErrorCode) BAi0w{
{ w6mYLK%
System.err.println("Error Code : " + nErrorCode); ZzR0k
} !>Q\Y`a,*
^vxNS[C`;
q?]KZ_a
//停止文件下载 aAn p7\7
public void siteStop() 017nhI
{ \xC#Zs[<
bStop = true; .Xe_Gp"x
for(int i=0;i<nStartPos.length;i++) `0q=Z],
fileSplitterFetch.splitterStop(); 7z/O#Fbs
4:b'VHW.
RwrRN+&s\
} z?|bs?HKS
} 8+Gwv SDU
//负责部分文件的抓取 >T0`( #Lm
**FileSplitterFetch.java #(+V&<K
*/ s+&0Z3+
package NetFox; sP%b?6
JlRNJ#h>
WI&}94w
import java.io.*; .VUnOdI
import java.net.*; =kK%,Mr
'`W6U]7>
zq?xY`E
public class FileSplitterFetch extends Thread { 8$X3J[_j
/?TR_>
2 1+[9
String sURL; //File URL Q~' \oWz
long nStartPos; //File Snippet Start Position UYW'pV
long nEndPos; //File Snippet End Position e$`hRZ%
int nThreadID; //Thread's ID WW^+X~Y
boolean bDownOver = false; //Downing is over r/P}j4)b7
boolean bStop = false; //Stop identical `@0AGSzUv
FileAccessI fileAccessI = null; //File Access interface *ywr_9
7;Q4k"h
;3bUgI}.J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3QdCu<eBZ
{ "i*gJFW|
this.sURL = sURL; V(io!8,
this.nStartPos = nStart; R)isWw4
this.nEndPos = nEnd; 6P,uy;PJ
nThreadID = id; N:+d=G`x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `YMd0*
} SdnO#J}{
BD^1V( I/
2vsV:LS.
public void run() /?z3*x
{ 9v8^uPA
while(nStartPos < nEndPos && !bStop) #<u;.'R
{ Ra H1aS(
:l iDoGDi
&rX#A@=
try{ C[#C/@
URL url = new URL(sURL); [9MbNJt 8~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3Z#WAhfS:
httpConnection.setRequestProperty("User-Agent","NetFox"); ?*7Mn`
String sProperty = "bytes="+nStartPos+"-"; -g|ji.
httpConnection.setRequestProperty("RANGE",sProperty); WA:r4V
Utility.log(sProperty); KU]o=\ak%
P46Q3EE
?gjx7TQ?
InputStream input = httpConnection.getInputStream(); v#X#F9C
//logResponseHead(httpConnection); .`v%9-5v
AR$SQ_4
)%n$_N n
byte[] b = new byte[1024]; MQ0rln?
int nRead; difX7)\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _F|}=^Z`
{ g+<[1;[-
nStartPos += fileAccessI.write(b,0,nRead); r}D#(G$
//if(nThreadID == 1) Jo~fri([%Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0!$y]Gr
} 3 5L0CM
n%4/@M
(-&d0a9N
Utility.log("Thread " + nThreadID + " is over!"); hv\Dz*XTs0
bDownOver = true; Y| ch ;
//nPos = fileAccessI.write (b,0,nRead); <l5m\A
} Cz9MXb]B
catch(Exception e){e.printStackTrace ();} 3hUP>F8
} VRD^>Gi
} MHye!T6fO\
2\gIjXX"
?N!kYTR%}
//打印回应的头信息 ~#}T|
public void logResponseHead(HttpURLConnection con) b`=g#B|
{ 6qT-
for(int i=1;;i++) rK:cUW0]X
{ y=EVpd
String header=con.getHeaderFieldKey(i); UEfY'%x
if(header!=null) X|ZAC!J5>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =_ b/g
Utility.log(header+" : "+con.getHeaderField(header)); ;/JXn
else 0'YP9-C3
break; g]`YI5
} wEJzLFCn
} v=cQ`nou
3T4HX|rC
n&?)gKL0g
public void splitterStop() Dh?I
{ Z,Us<du
bStop = true; WjM7s]ZRv
} (+/d*4
NuD|%Ebs
MxKTKBxQ
} ]yZ%wU9!
*)6\V}`
;^E_BJm
/* pIYXYQ=Z
**FileAccess.java .uxM&|0H
*//文件访问(定位，写) aJA(UN45
package NetFox; R<{Vgy
import java.io.*; ;z N1Qb
+{I" e,Nk
e t@:-}
public class FileAccessI implements Serializable{ 0_MtmmL.
a'dlAda
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a_?b<
RandomAccessFile oSavedFile; X?n=UebO^
long nPos; : T7(sf*!*
VO=Ibu&X
uZ\+{j=
public FileAccessI() throws IOException CS(2bj^6D
{ p:W]
this("",0); .jk A'i@
} ;e/F( J
#d-zH:uq
eNVuw:Q+
public FileAccessI(String sName,long nPos) throws IOException TB+k[UxB
{ k,k>w#&
oSavedFile = new RandomAccessFile(sName,"rw"); P R3Arfle
this.nPos = nPos; 1# z@D(
oSavedFile.seek(nPos); @|Yn~PwKs
} ka8Y+Gs
voN~f>
LyWY\K a
public synchronized int write(byte[] b,int nStart,int nLen) *pv<ZF0>
{ q^Oj/ws
int n = -1; dIYf}7P
try{ 9!W$S[ABRB
oSavedFile.write(b,nStart,nLen); +jF2{"
n = nLen; q#8yU\J|,
} 2.b,8wT/
catch(IOException e) WulyMcJ
{ bE'{zU}o
e.printStackTrace (); 0gaHYqkA>}
} OWT%XUW=
q`IY;"~
$[,4Ib_|
return n; Rb&9!z
} gBcs
]S[?tn
0F/[GZ<k
} 3]mprX'
T]-MrnO
[xr^t1
/* 09jE7g @X}
**SiteInfoBean.java LR>s2zu-
*/ !U m9ceK
package NetFox; shH2/.>
js5VgP`
P~=yTW
public class SiteInfoBean { |vl~B|",
sVw:d_ E
m:[I$b6AY
private String sSiteURL; //Site's URL p^<(.+P4
private String sFilePath; //Saved File's Path jga\Ry=nw
private String sFileName; //Saved File's Name 9,`i[Dzp
private int nSplitter; //Count of Splited Downloading File rVoV@,P
^4^N}7>5
BOG.[?yx
public SiteInfoBean() _avf%OS
{//nSplitter的缺省值为5 |.0~'
//default value of nSplitter is 5 _OuNX.yrG
this("","","",5); M.- {->
} ?dCwo;~
4dPTrBQ?
d9;&Y?fp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &|#[.ti1
{ B#jnM~fJz
sSiteURL= sURL; nv@z;#&
sFilePath = sPath; k)S1Zs~G
sFileName = sName; 0 h!Du|?
this.nSplitter = nSpiltter; #5)/B
v>B412l
__.MS6"N
} f?)7MR=
<;PKec
J*$%d1
public String getSSiteURL() /[FDiJH2
{ Zdqm|_R[
return sSiteURL; |;wc8;
} gI;"PkN
)c' 45bD
\\KjiT'
public void setSSiteURL(String value) NF6xKwRU]_
{ {Fw"y %a^
sSiteURL = value; Rq5'=L
} s~A-qG>
Lxv4w
U\?D;ABQ%
public String getSFilePath() ~. vridH
{ S1U0sP@o
return sFilePath; (!5Ta7X
} JpC=ACF
TsK!36cg
[-_{3qq<e
public void setSFilePath(String value) =IsmPQKi
{ nWIZ0Nde'
sFilePath = value; rtJER?A
} K!&W}_@l
'lA}E
BKg8p]`+
public String getSFileName() .s*N1 U?h
{ F8?2+w@P
return sFileName; '@.6Rd 8
} /x ?@Mn>
fe/;U=te
.b3h?R*&
public void setSFileName(String value) JVX)>2&$
{ h{^v756L
sFileName = value; )4=86>XJT
} OA&'T*)-A6
Gc`PO
H@1'El\9
public int getNSplitter() $kTm"I
{ x:MwM?
return nSplitter; s"=TM$Vb
} I0~'z f
.h=n [`RB
1Z< ^8L<
public void setNSplitter(int nCount) 8>eYM
{ uS`}
nSplitter = nCount; O>]i?
} BJux5Nh
} r{R<J?Y
HqW /
.t1:;H b
/* w{*kbGB8s7
**Utility.java KSchgon0V
*/ qKfUm:7Q_
package NetFox; eavn.I8J
Ra|P5
l!x+K&
public class Utility { zX_F+"]THt
O3o^%0
Xs052c|s
public Utility() metn&
{ mxgT}L0i
t8-Nli*O
)hrsA&1w
} $WIVCp
\nEMj,)
//线程睡眠 /=p[k^A
public static void sleep(int nSecond) =Q(J!f
{ !~vK[G(R
try{ PG63{
Thread.sleep(nSecond); i;1pw_K
} @FN|=?8%
catch(Exception e) nKm# kb
{ p [C 9g
e.printStackTrace (); 0 MK}
} 5VTVx1P[8
} aG }oI!
$vu*# .w
//日志 -n9&W
public static void log(String sMsg) ^\ x'4!W
{ fY&TI}Y
System.err.println(sMsg); #!F>cez
} ?A|JKOst]
wPM>-F
IQO|)53)
public static void log(int sMsg) v-z%3x.f
{ Ih:Q}V#6
System.err.println(sMsg); dzOco)y
} 3LETzsJ
} gvR]"h
6NX#=A
H}kZ;8
/* (s;W>,~q
**TestMethod.java U~][ ph
*/ Wm6qy6HR
package NetFox; ~Q_7HJ=^$
$.Tn\4z&
5K1cPU~o_b
public class TestMethod { O"'xAPQW
'd$RNqe
ts,r,{
public TestMethod() */M`KPW
{ ///xx/weblogic60b2_win.exe 53:~a
try{ <8b1OdA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -SM_JR3<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $$m0mK
SiteFileFetch fileFetch = new SiteFileFetch(bean); pZ>yBY?R8>
fileFetch.start(); [o<hQ`&
} v>wN O
catch(Exception e){e.printStackTrace ();} q|<B9Jk
}8 z:L<
$!*>5".A
} !Sn|!:N4
?{ExBZNa
! eZls
public static void main(String[] args) wU+r]SK@
{ \~*<[.8~
new TestMethod(); C})Dvh
} Vq+7 /+2"
} R)66qRf
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