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)); \l=A2i7TQ
} <IZr..|O
for(int i=0;i<nEndPos.length-1;i++) 4M"'B A<
{ &5HI
nEndPos = nStartPos[i+1]; \ ERBb.
} I]HYqI
nEndPos[nEndPos.length-1] = nFileLength; ^X#)'\T
} ~[!Tpq5
} d*u3]&?x&f
~Xx}:@Ld
9vi+[3s/=;
//启动子线程 `V/kM0A5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; # 9bw'm
for(int i=0;i<nStartPos.length;i++) jXx~5
{ MZ)lNU l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fbI5!i#lz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VKPsg
nStartPos,nEndPos,i); #: EhGlq8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &x (D%+
fileSplitterFetch.start(); Vb\^xdL>
} l )r^|9{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +v%+E{F$+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ([m4dr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &xr(Kb
nEndPos = " + nFileLength); MNh:NFCRA
// fileSplitterFetch[nPos.length-1].start(); .D7Gog3^<
FS7D
bz:En'2>F
//等待子线程结束 %M_F/O
//int count = 0; ?RE"<L
//是否结束while循环 ^!m%:r7Dr
boolean breakWhile = false; 7LaRFL.,kO
nF-l4=
9n5uO[D
while(!bStop) s&%r?
{ >d;U>P5.
write_nPos(); mJ8EiRSE
Utility.sleep(500); JrxQ.,*i
breakWhile = true; C\[:{d
g6gwNC:aF
lNe5{'OrO
for(int i=0;i<nStartPos.length;i++) $LBgBH&z
{ Ct(^nn$A
if(!fileSplitterFetch.bDownOver) -{oZK{a1
{ 6d5q<C_3t
breakWhile = false; OHY|< &*
break; P e} T
} MO1H?Uhx
} }L`Z<h*H
if(breakWhile) tPk>hzW
break; K=4|GZ~p}`
)eX{a/Be
ZP:+'\&J
//count++; B_@p@6z
//if(count>4) \+ Ese-la
// siteStop(); `/G9*tIR8g
} v/7^v}[<
|@B|o-
"-HWw?rx/
System.err.println("文件下载结束！"); Cpn!}!Gnf
} V\c`O
catch(Exception e){e.printStackTrace ();} l:a#B
} l?X)]1
do.XMdit
%xXb5aY
//获得文件长度 ;wHyX)&X$
public long getFileSize() ##" Hui
{ U@}r?!)"f
int nFileLength = -1; I,/E.cRV<
try{ }?CKE<#%
URL url = new URL(siteInfoBean.getSSiteURL()); 7$Cv=8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]<;y_
httpConnection.setRequestProperty("User-Agent","NetFox"); Co/04F.
8qUNh#
!Ks<%; rb
int responseCode=httpConnection.getResponseCode(); 4`sW_ ks
if(responseCode>=400) bz`rSp8h
{ 2%-/}'G*
processErrorCode(responseCode); bIuOB|
return -2; //-2 represent access is error k]c$SzJ>/
} 9 H>JS
R$2\Xl@qQF
SO`b+B
String sHeader; 0.~s>xXp
rj29$d?Y9
$%1oZ{&M
for(int i=1;;i++) [KEw5-=i@
{ a!&<jM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^_=bssaOd
//Utility.log(in.readLine()); <Ug1g0.
sHeader=httpConnection.getHeaderFieldKey(i); Om8Sgy?
if(sHeader!=null) .sZ"|j9m
{ m&--$sr
if(sHeader.equals("Content-Length")) ,C^u8Z|T
{ |-]'~@~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b~!Q3o'W
break; =_$Hn>vO
} {T5u"U4
} &8JK^zQq
else ,/eAns`ZU
break; DLoH.Fd
} As|e=ut(
} [n$6T
catch(IOException e){e.printStackTrace ();} nYTPcT4x|
catch(Exception e){e.printStackTrace ();} ,UxAHCR~9
.bNG:y>
riSgb=7q9
Utility.log(nFileLength); ' $"RQ=
3oApazH*
50Ov>(f@7
return nFileLength; /kqa|=-`q
} % 3<7HY]~
m :2A[H+
cJ'OqV F
//保存下载信息（文件指针位置） 55zy]|F"
private void write_nPos() -T>i5'2)
{ +6(\7?
try{ wu0q.]
output = new DataOutputStream(new FileOutputStream(tmpFile)); eI/5foA
output.writeInt(nStartPos.length); Z)<lPg!YAR
for(int i=0;i<nStartPos.length;i++) G^le91$
{ |}o3EX
// output.writeLong(nPos); CWSc#E
output.writeLong(fileSplitterFetch.nStartPos); -o@L"C>
output.writeLong(fileSplitterFetch.nEndPos); #1p\\Av
} C/q!!
output.close(); {vp*m:K
} 2~%^y6lR
catch(IOException e){e.printStackTrace ();} n]jw!;
catch(Exception e){e.printStackTrace ();} nPUD6<bF
} M[QQi2:&
U.N?cKv
|u+!CR
//读取保存的下载信息（文件指针位置） ur[^/lxx0
private void read_nPos() FzG>iC}
{ <4582x,G
try{ &W{v(@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $t0JfDd6Ky
int nCount = input.readInt(); .Gb!mG
nStartPos = new long[nCount]; &mm!UJ
nEndPos = new long[nCount]; U|x#'jGo'
for(int i=0;i<nStartPos.length;i++) =X7_!vSv
{ -L!lJ
nStartPos = input.readLong(); 8k;il54#
nEndPos = input.readLong(); k`J|]99Wb
} \susLD
input.close(); 7 4]qz,
} } g%v<'K
catch(IOException e){e.printStackTrace ();} i:1 @ vo
catch(Exception e){e.printStackTrace ();} &_74h);2I:
} KtHkLYOCG
aP#/%
;3o7>yEv
private void processErrorCode(int nErrorCode) 1:J+`mzpl
{ c7RQ7\
System.err.println("Error Code : " + nErrorCode); n/S+0uT
} !@ {sM6U
< pZwM
jwP5pu
//停止文件下载 *D.Ajd.G
public void siteStop() a4pewg'
{ _PSOT5{
bStop = true; L$,yEMCe
for(int i=0;i<nStartPos.length;i++) lSc=c-iOv
fileSplitterFetch.splitterStop(); kT:I.,N
!;0K=~(Y^
"F[7b!>R
} D"%>
} [2E(3`-u
//负责部分文件的抓取 h}kJ,n
**FileSplitterFetch.java IhOAMH1
*/ lc3Gu78 A/
package NetFox; (>NZYPw^3
ZB`d&!W>
7VL|\^Y`q
import java.io.*; ]sJC%/
import java.net.*; dT[JVl+3=
'u~0rMe4})
;#:AM;
public class FileSplitterFetch extends Thread { W1EYVXN
O8SE)R~
{`,)<R>}
String sURL; //File URL X-#&]^d
long nStartPos; //File Snippet Start Position 5DVYHN9c|
long nEndPos; //File Snippet End Position zTc*1(^
int nThreadID; //Thread's ID 6q6xqr:W
boolean bDownOver = false; //Downing is over "c|Rpzs[
boolean bStop = false; //Stop identical z+-o}i
FileAccessI fileAccessI = null; //File Access interface w ?*eBLJ(G
e[s}tjx
/(.:l +[w[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9g>)7Ne
{ 9\c]I0)3p
this.sURL = sURL; AI`k }sA~
this.nStartPos = nStart; ~?FhQd\Q
this.nEndPos = nEnd; L9lJ4s
nThreadID = id; Hf\sF(, (
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `G_~zt/
} 6su~SPh
1m#.f=u{R
`j(._`8%a
public void run() bwH[rT!n
{ CH&{x7$he
while(nStartPos < nEndPos && !bStop) *tgu@9b
{ Jv+w{"&
@XXPJq;J
&K{8- t
try{ n:P:im?,y*
URL url = new URL(sURL); 9)NKI02M|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L!lmy&1
httpConnection.setRequestProperty("User-Agent","NetFox"); N2"B\
String sProperty = "bytes="+nStartPos+"-"; p@nj6N.--
httpConnection.setRequestProperty("RANGE",sProperty); 6(rN(C
Utility.log(sProperty); /s} "0/Y\
<|jh3Hlp
rM"27ud[`_
InputStream input = httpConnection.getInputStream(); cw{TS
//logResponseHead(httpConnection); q\]X1N
dC{dw^
^9:`D@Z+
byte[] b = new byte[1024]; ao"2kqa)r
int nRead; #[bL9R5NC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )38%E;T{X
{ .Zv~a&GE
nStartPos += fileAccessI.write(b,0,nRead); &UOxS W
//if(nThreadID == 1) >Vjn]V5y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BEvY&3%l
} "`V@?+3
%,_ZVgh0
XhHgXVVGG<
Utility.log("Thread " + nThreadID + " is over!"); ekL;SN
bDownOver = true; }!oEjcX'
//nPos = fileAccessI.write (b,0,nRead); <D~hhGb
} $3G^}A"
catch(Exception e){e.printStackTrace ();} e,/]]E/o
} ld@+p
} uC^)#Y\"
i7XY3yhC
3NLn}
//打印回应的头信息 LhbdvJAk@
public void logResponseHead(HttpURLConnection con) iX]OF.:
{ mn?F;=qE
for(int i=1;;i++) pE)NSZ
{ qBX_v5pvVA
String header=con.getHeaderFieldKey(i); dX cbS<
if(header!=null) )|xu5.F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~p?ArZb
Utility.log(header+" : "+con.getHeaderField(header)); -&>V.hi7
else ;+E]F8G9r
break; W_`]7RO8
} {MUiK5:
} ,bl }@0A
]O"f%
0N$7(.
public void splitterStop() /B@{w-N
{ /=m AVA
bStop = true; l5{60$g
} i *.Y
m7'<k1#"Y
<J&S[`U!
} MF4(
k56Qas+3=
PlzM`g$A
/* =#V^t$
**FileAccess.java #y:D{%Wp
*//文件访问(定位，写) (w hl1
package NetFox; 1RYrUg"s"
import java.io.*; ][$I~nRf
1P!)4W
1l$Ei,9
public class FileAccessI implements Serializable{ aZ4EcQ@-$]
p@^G)x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RhE~-b[X
RandomAccessFile oSavedFile; {=ox1+d
long nPos; \"a{\E,{;
4`5yrCd
?uq`|1`
public FileAccessI() throws IOException t>\sP
{ UucI>E3?P{
this("",0); :25LQf^nz
} W "'6M=*
A`Z/B[)
QhZg{v[d
public FileAccessI(String sName,long nPos) throws IOException CQ!pt@|d
{ 1hG#
oSavedFile = new RandomAccessFile(sName,"rw"); t WI-
this.nPos = nPos; la3B`p
oSavedFile.seek(nPos); P1-eDHYw
} arYq$~U
? }M81
;o9h|LRs
public synchronized int write(byte[] b,int nStart,int nLen) @sXv5kZ:
{ 8<6H2~5<
int n = -1; ==dKC;
try{ *LEy#N
oSavedFile.write(b,nStart,nLen); e}UQN:1
n = nLen; bF"l0 jS
} HuevDy4
catch(IOException e) u:l-qD9=(
{ yix[zfQt0
e.printStackTrace (); [;u#79aE
} ]q]xU,
;+9OzF ;
IO\4dU)
return n; gQn%RPMh
} UkL1h7}a\
%fj5;}E.
@Vm*b@
} n Nt28n@
VXeO}>2S
K zWo}tT
/* yb`PMjj15
**SiteInfoBean.java 5;a*Xf%V
*/ .xRdKt!p
package NetFox; zPby+BP
r_T)|||v
[X(4( 1i
public class SiteInfoBean { 6Tl6A>%s
5n@YNaoIb
XiW1X6
private String sSiteURL; //Site's URL ;*(-8R/
private String sFilePath; //Saved File's Path GK@OdurAR
private String sFileName; //Saved File's Name vF72#BNs
private int nSplitter; //Count of Splited Downloading File 'cD?0ou`o
M+/G>U
$V~@w.-Z#
public SiteInfoBean() H"A%mrb
{//nSplitter的缺省值为5 Gl~l
//default value of nSplitter is 5 +?_!8N8
this("","","",5); )^j_O^T5
} '}.Yf_
.biq)Le
gaF6j!p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ATs_d_Sz
{ /_C2O"h
sSiteURL= sURL; GY~$<^AK
sFilePath = sPath; \-\>JPO~<
sFileName = sName; S=UuEmU5N
this.nSplitter = nSpiltter; y'R}
%8'8XDq^8
dOhSqx56
} RZa/la*
'a~@q~!
xTHD_?d
public String getSSiteURL() .t8)`MU6.
{ 2b"*~O;
return sSiteURL; LF dvz0
} ) c@gRb~
GP};~
!]4u"e
public void setSSiteURL(String value) iU)I"#\l'k
{ (,|,j(=]
sSiteURL = value; Z\!,f.>g
} UK=ELvt]
S=@+qcI
{:X'9NEE
public String getSFilePath() ]J7qsMw
{ i)i>Ulj*i
return sFilePath; :qzg?\(
} YI0 wr1N
u64#,mC[*
",#.?vT`
public void setSFilePath(String value) -cgO]q+Oq
{ k/K)nH@)
sFilePath = value; \:vF FK4a
} )%(ZFn}
8v$q+Wic
)GP;KUVae
public String getSFileName() r%,?uim#
{ %cF`x_h[j
return sFileName; u0C:q`;z
} wkg4I.
N?\X2J1
8Pn
public void setSFileName(String value) ni;_Un~
{ =EJ&=t
sFileName = value; ~k*]Z8Z
} (,Y[2_Zv
3.&BhLT
ZrN(Mp
public int getNSplitter() Yh<F-WOo2
{ Gek?+|m
return nSplitter; G]lGoa}]`u
} LuS@Kf8N+
k+QGvgP[4@
N[{rsUBd
public void setNSplitter(int nCount) k!c7eP"%8^
{ N/a4Gl(
nSplitter = nCount; >S5J^c
} 6-U_TV
} JVAyiNIH>M
(5T>`7g8
0R?1|YnB
/* (UkP AE
**Utility.java oO2DPcK
*/ )5|9EXh
package NetFox; 91R#/i
**q8vhJM
vC]X>P5Px
public class Utility { M9"Bx/
W;u.@I&
(-C)A-Uo&
public Utility() tU4#7b:Y
{ {;$oC4
C[FHqo9M?H
d9{lj(2P
} %. 1/#{
((M,6Q}
//线程睡眠 yP"2.9\erH
public static void sleep(int nSecond) E'6>3n
{ `KQx#c>'
try{ ;4O[/;i
Thread.sleep(nSecond); LnR>!0:c
} 8xy8/UBIk0
catch(Exception e) =2!p>>t,d;
{ -2hirA<^
e.printStackTrace (); #|9W9\f,
} :82T!
} &8IBf8
CW1l;uwtU
//日志 7Kw'Y8
public static void log(String sMsg) l b(
{ CCTU-Xz/
System.err.println(sMsg); '_v~+
} e-dkvPr
BA\aVhmx
}geb959
public static void log(int sMsg) YZ~MByu
{ \[9VeqMU
System.err.println(sMsg); H-_gd.VD
} "7cty\
} ~[CFs'`(2
j\C6k
e!VtDJDS
/* xpdpD
**TestMethod.java TgkVd]4%
*/ Nh\vWAz9
package NetFox; =j>xu|q
9E7G%-
,X!6|l8
public class TestMethod { '#6eUb
&nEL}GM)E
;!<}oZp{
public TestMethod() 4*EMd!E=<
{ ///xx/weblogic60b2_win.exe b 3x|Dq.
try{ 0B.Gt&Oal
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vF^d40gV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~qinCIj
SiteFileFetch fileFetch = new SiteFileFetch(bean); wR%Ta-
fileFetch.start(); UA<Fxt
} z0[@O)Sj
catch(Exception e){e.printStackTrace ();} ;UQza ]i
!q\8`ss
5`^@k<
} P&0eu
wI@87&
P j
public static void main(String[] args) "3RFyi
{ !!C/($
new TestMethod(); I=dG(?#7%
} R XCn;nM4
} [ <X%
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