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)); AH7}/Rc
} 7.j?U
for(int i=0;i<nEndPos.length-1;i++) Fq<A
{ V&2l5v
nEndPos = nStartPos[i+1]; 2eY_%Y0
} bwMm#f
nEndPos[nEndPos.length-1] = nFileLength; qqY"*uJ'
} ItrDJ'
} B%6)}Nl[
Z=o2H Bm7
3bH'H*2
//启动子线程 aeM+ d`f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :tg)p+KB
for(int i=0;i<nStartPos.length;i++) ?GR"FmB(
{ ZKTz ,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;dgp+
nStartPos,nEndPos,i); 7[XRd9a5(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +\ .Lp 5
fileSplitterFetch.start(); Qe:seW
} CkQ3#L<2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _)m]_eS._
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0 /U{p,r6`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Kis"L(C
nEndPos = " + nFileLength); h3 }OX{k
// fileSplitterFetch[nPos.length-1].start(); ?%[@Qb=2
'7@zGk##(
Lnl=.z`jK
//等待子线程结束 T:yE(OBf
//int count = 0; Eo]xNn/g
//是否结束while循环 v PG},m~-
boolean breakWhile = false; hhc,uJ">!
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while(!bStop) y766; X:J
{ lq;Pch
write_nPos(); 8'io$6d=
Utility.sleep(500); hMD|#A-<
breakWhile = true; SoSb+\*@h
KB(8f*
M%P:n/j
for(int i=0;i<nStartPos.length;i++) )1`0PJoHE
{ w_K1]<Q*
if(!fileSplitterFetch.bDownOver) .p" xVfi6
{ $DaNbLV
breakWhile = false; r52gn(,
break; 6mxfLlZ
} ; )@~
} ~V1E0qdAE
if(breakWhile) }N6.Uu5zI
break; `7V]y-
56kI 5:
[5Mr@f4I
//count++; ~U&AI1t+J
//if(count>4) ,(^*+G.i
// siteStop(); ope^~+c~\
} ~dTrf>R8M
x7<K<k;s
M gi,$H
System.err.println("文件下载结束！"); @Z:l62l=bE
} 6A+nS=
catch(Exception e){e.printStackTrace ();} mtcw#D
} T!)(Dv8@F
{q^[a-h>
i2SR{e8:GF
//获得文件长度 H9Q&tl9
public long getFileSize() '3^'B03
{ *_\_'@1|J)
int nFileLength = -1; Yufc{M00
try{ $suzW;{#
URL url = new URL(siteInfoBean.getSSiteURL()); v O_*yh1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :nOFR$W
httpConnection.setRequestProperty("User-Agent","NetFox"); d)Y}>@:W
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w@w(-F!%l
int responseCode=httpConnection.getResponseCode(); U26}gT)
if(responseCode>=400) 5vnrA'BhBU
{ <bEbweQrgm
processErrorCode(responseCode); m GYoM
return -2; //-2 represent access is error k!'a,R:
} ,/|T-Ka
m#\dSl}
bq0zxg%
String sHeader; UH"%N)[
Em~>9f ?Q(
}`m/bgtFX
for(int i=1;;i++) Ao&"r[oJSv
{ YNsJZnGr8#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $kp{Eg '
//Utility.log(in.readLine()); hZt!/?dc
sHeader=httpConnection.getHeaderFieldKey(i); Bh-ym8D
if(sHeader!=null) %:* YO;dw'
{ :&."ttf=
if(sHeader.equals("Content-Length")) 8[{ Vu0R
{ @GW#&\yM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g}(L;fy>7
break; !%%6dB@%t
} Se =`N
} *VxgARIL
else %6f*{G w
break; /aZ`[m2
} z*%q@]ym
} smo~7;
catch(IOException e){e.printStackTrace ();} fVpMx4&F
catch(Exception e){e.printStackTrace ();} u;2[AQ.
GC}==^1
L) T (<
Utility.log(nFileLength); Qh\60f>0
a<bwzX|.
T1=fNF
return nFileLength; "@2-Zdrr1<
} S;`A{Mow
Q>Yjy!.<^
VRB;$
//保存下载信息（文件指针位置） ^s"R$?;h
private void write_nPos() dDLeSz$b
{ I51@QJX
try{ NqWdRU
output = new DataOutputStream(new FileOutputStream(tmpFile)); nZYBE030
output.writeInt(nStartPos.length); /f;~X"!
for(int i=0;i<nStartPos.length;i++) t;\Y{`
{ XU(eEnmom
// output.writeLong(nPos); 4@ai6,<
output.writeLong(fileSplitterFetch.nStartPos); o0KL5].
output.writeLong(fileSplitterFetch.nEndPos); ##"HF
} Oxd]y1
output.close(); 2g! +<YZ~
} j|#Bo:2km
catch(IOException e){e.printStackTrace ();} 9p(.A$
catch(Exception e){e.printStackTrace ();} %._.~V
} H"WprHe
c9h6C
Wvf ^N(
//读取保存的下载信息（文件指针位置） C1QA)E['V
private void read_nPos() E hMNap}5"
{ z-)O9PV
try{ 1yu4emye4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [`7ThHX
int nCount = input.readInt(); mc\"yC^s
nStartPos = new long[nCount]; B^^#D0<
nEndPos = new long[nCount]; }-=|^
for(int i=0;i<nStartPos.length;i++) Uz]|N6`
{ YNi.SXH
nStartPos = input.readLong(); 5$C-9
nEndPos = input.readLong(); T9[Q
} Btcy)LRk
input.close(); +52{-a,>
} -nV9:opD
catch(IOException e){e.printStackTrace ();} I b5rqU\
catch(Exception e){e.printStackTrace ();} E~"y$Fqe
} o?\?@H
/%io+94
C;^X[x%h7$
private void processErrorCode(int nErrorCode) ~Z'?LV<t
{ c{w2Gt!
System.err.println("Error Code : " + nErrorCode); qlPT Ll
} 0LJv'
FU4L6n
f) L
//停止文件下载 )lDD\J7
public void siteStop() IjnU?Bf
{ d/~9&wLSb
bStop = true; .%
for(int i=0;i<nStartPos.length;i++) z~s PXGb
fileSplitterFetch.splitterStop(); 13x p_j
`VguQl_,gA
b4N[)%@
} 7B66]3v
} aK^q_ghh[
//负责部分文件的抓取 T]~xj4
**FileSplitterFetch.java pTLCWbF?
*/ 6.yu-xm
package NetFox; x7 ,5
|P?*5xPB
`r 3
import java.io.*; jAlv`uB|G"
import java.net.*; ; BHtCuY
-aCKRN85
O?#7N[7
public class FileSplitterFetch extends Thread { 4{|"7/PE1
^} >w<'0
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String sURL; //File URL Ab.(7GFK
long nStartPos; //File Snippet Start Position $/Uq0U
long nEndPos; //File Snippet End Position {]4LULq
int nThreadID; //Thread's ID sK?twg;D*|
boolean bDownOver = false; //Downing is over HJ.-Dg5U
boolean bStop = false; //Stop identical KHvYUTY
FileAccessI fileAccessI = null; //File Access interface ,Ma^&ypH
j^RmrOg,
NC6&x=!3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H3-hcx54T
{ e~"U @8xk~
this.sURL = sURL; ;#< 0<
this.nStartPos = nStart; 19%imf
this.nEndPos = nEnd; \1M4Dl5!
nThreadID = id; 0?|<I{z2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NL+N%2XG7
} wi{3/
O+x!Bg7
+X 88;-
public void run() yyTnL 2Y9
{ ]u/sphPe
while(nStartPos < nEndPos && !bStop) h^P#{W!e\
{ ;L ^o*`
YKK*ER0
&s!@29DXR
try{ 2=!RQv~%
URL url = new URL(sURL); Y"$xX8o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b4Ekqas
httpConnection.setRequestProperty("User-Agent","NetFox"); 6[AL|d DK
String sProperty = "bytes="+nStartPos+"-"; S~G]~gt
httpConnection.setRequestProperty("RANGE",sProperty); q{x8_E!L
Utility.log(sProperty); !ULn7\@
:e+jU5;]3
<<O$ G7c
InputStream input = httpConnection.getInputStream(); .O<obq~;C
//logResponseHead(httpConnection); 9_h[bBx-'Q
ZXPX,~ 5o
p!AAFmc
byte[] b = new byte[1024]; !C.4<?*|
int nRead; sU^1wB Rj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Pr C{'XDlU
{ a(ZcmYzXU
nStartPos += fileAccessI.write(b,0,nRead); {Qj~M<@3
//if(nThreadID == 1) @oGcuE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0#gK6o!
} :7;@ZEe
H3oFORh
P16~Qj
Utility.log("Thread " + nThreadID + " is over!"); VuZr:-K/
bDownOver = true; -yNlyHv9
//nPos = fileAccessI.write (b,0,nRead); Z0r'S]fe
} yEy6]f+>+
catch(Exception e){e.printStackTrace ();} \o3gKoL%
} M X]n&
} KwVbbC3
t"I77aZ$A
V>3X\)qu
//打印回应的头信息 XQw9~$
public void logResponseHead(HttpURLConnection con) )0k53-h&
{ }c:M^Ff
for(int i=1;;i++) G=bCNn<
{ [()koU#w.
String header=con.getHeaderFieldKey(i); 5SQ8}Or3
if(header!=null) [mueZQyI?0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YuwI&)l
Utility.log(header+" : "+con.getHeaderField(header)); |;{6&S
else 7_[L o4_
break; >=w)x,0yX
} 2MK-5Kg
} dlnX_+((KC
/G`]=@~
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public void splitterStop() xN'I/@ kb
{ a?oI>8*
bStop = true; &uVnZ@o42
} RT8 ?7xFc
G^@5H/)
|6y
} +aAc9'k
I5W~g.<6
;5AcFB
/* xD=csJ'(
**FileAccess.java ?Z}&EH
*//文件访问(定位，写) EKN~H$.
package NetFox; \z)%$#I
import java.io.*; JK]PRDyD
%@Jsal'
1{.9uw"2S
public class FileAccessI implements Serializable{ X5w$4Kj&4l
:rP=t ,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 asqV~n
RandomAccessFile oSavedFile; iU:cW=W|M\
long nPos; ?\n> AC
\ B%+fw
V28M lP
public FileAccessI() throws IOException yIE!j%u
{ z0Z%m@
this("",0); !dT4
} 5~S5F3
lNv|M)I
s,_m{ to
public FileAccessI(String sName,long nPos) throws IOException =i3n42M#
{ !ubD/KE
oSavedFile = new RandomAccessFile(sName,"rw"); lmhLM. 2
this.nPos = nPos; 2 ? 4!K.
oSavedFile.seek(nPos); :~SyL!
} J9 I:Q<;
_(zG?]y0P
GKeU%x
public synchronized int write(byte[] b,int nStart,int nLen) 4 H&#q>
{ DW3G
int n = -1; og>uj>H&
try{ f,Ghb~y
oSavedFile.write(b,nStart,nLen); !TcJ)0
n = nLen; &,)&%Sg[
} A/?7w
catch(IOException e) c4zR*
{ 3r1*m +
e.printStackTrace (); ,tRj4mx
} fd9k?,zM
L\iFNT}g`
VG~Vs@c(
return n; :MDKC /mC
} @KUWxFak
=WJNWt>
`QY)!$mUIF
} ;GD]dW#
8JUwf
4`=mu}Y2
/* |+"(L#wk
**SiteInfoBean.java t3^&;&[
*/ U`s{Jm
package NetFox; 3=;<$+I6
R/a*LSe@&
(4-CF3D
public class SiteInfoBean { CTA3*Gn
(uidNq
hFBe,'3M
private String sSiteURL; //Site's URL ]}X
private String sFilePath; //Saved File's Path J?$,c4;W2
private String sFileName; //Saved File's Name '4<1 1(U
private int nSplitter; //Count of Splited Downloading File P1f[%1
-D~%|).'
|vzl. ^"-
public SiteInfoBean() h@wgd~X9
{//nSplitter的缺省值为5 Z5]>pJFq,
//default value of nSplitter is 5 Jfl!#UAD|n
this("","","",5); 6-ils3&
} <=C?e<Y
@=f\<"$vt
3irl (;v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '/%H3A#L
{ {+b7sA3
sSiteURL= sURL; p{dj~ &v
sFilePath = sPath; Mrb)
sFileName = sName; W=4FFl[
this.nSplitter = nSpiltter; m~ee/&T
a"u0Q5J
3HK\BS
} ,9 a
J9S>yLQK
6D_D';o
public String getSSiteURL() o3}3p]S\
{ }SCM I4\
return sSiteURL; )}O8?d`
} Wh{tZ~c
7E!5G2XX~~
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public void setSSiteURL(String value) r9G>jiw8
{ L9#g)tf 8T
sSiteURL = value; jZrq{Z<
} ~WV"SaA)*U
]')RMg zM*
IV)j1
public String getSFilePath() 18:%~>.!
{ 0+b1vhQ
return sFilePath; #C@FYOf*
} ,5<Cd,`*
.(2ik5A%9
;i+#fQO7Q
public void setSFilePath(String value) @pU)_d!pJ
{ %ULr8)R;
sFilePath = value; Dv`c<+q(#
} \xoP)Ub>
0#^v{DC
<1M-Ro?5k
public String getSFileName() ;t`&n['N>
{ U:_^#\p
return sFileName; \1Em`nvOX
} r",GC]
sCHJ&>m5-
NQ2E
public void setSFileName(String value) D.XvG_
{ FzC'G57Kl
sFileName = value; GWip-wI
} KKf
P7/X|M z
FaJ&GOM,
public int getNSplitter() M\Kx'N
{ m`r(p"
return nSplitter; 3=ymm^
} u> 7=AlWF-
9'q*:&qq
<Q?F?.^e
public void setNSplitter(int nCount) UFuX@Lu0
{ $iz|\m
nSplitter = nCount; _:27]K:
} x-3\Ls[I
} <2qr}K{'A
Hj,A5#|=J
P7~>mm+
/* ;4~hB
**Utility.java W5MTD]J
*/ Q]>.b%s[
package NetFox; 1&Zj
~&bq0(
12LL48bi
public class Utility { Z#\P&\`1z
u;c?d!E
\)|hogI|f
public Utility() !C:$?oU
{ M=r)I~
5XBH$&Td
Ph>%7M%
} +srGN5!
')3 bl3:
//线程睡眠 c0u^zH<
public static void sleep(int nSecond) DR<9#RRD
{ G'A R`"F
try{ 0"bcdG<}
Thread.sleep(nSecond); ea')$gR
} C3YT1tK
catch(Exception e) w`zTR0`
{ E^eVvP4uC@
e.printStackTrace (); N?"]
} @sC`!Rmy'-
} kPLxEwl
W6/yn
//日志 :6\qpex
public static void log(String sMsg) ]?[fsdAQW
{ e^D]EA]%
System.err.println(sMsg); FJP-y5
} s-T\r"d=j
0:Ol7
)P|),S,;Z
public static void log(int sMsg) "LTad`]<Ro
{ s!7y
System.err.println(sMsg); k+pr \d~
} p=}Nn(
} 65Yv4pNL
C>*u()q>4h
?<'}r7D
/* #4 pB@_
**TestMethod.java SI-Ops~e
*/ 'SF<_aS(
package NetFox; 81Z) eO#
^$hH1H+V
>V}#[/n
public class TestMethod { V33T+P~j
FQ5U$x.[P
wDe& 1(T^
public TestMethod() A2jUmK.&
{ ///xx/weblogic60b2_win.exe q5)O%l!
try{ fmDCPkj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [K0(RDV)%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K(,F~.<
SiteFileFetch fileFetch = new SiteFileFetch(bean); [E juUElr
fileFetch.start(); 4@# `t5H
} ._{H~R|
catch(Exception e){e.printStackTrace ();} %Y*Ndt4
wcY?rE9
JrRH\+4K
} j HJ`,#
L0WN\|D
b!5~7Ub.No
public static void main(String[] args) XuM'_FN`A<
{ 2!=f hN
new TestMethod(); *YuF0Yt
} bAtSVu
} 7! INkH]
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