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)); [] el4.J,
} xz,o Mlw
for(int i=0;i<nEndPos.length-1;i++) 10)RLh|+
{ @1xIph<z
nEndPos = nStartPos[i+1]; !^o{}*]Pi
} e^,IZ{
nEndPos[nEndPos.length-1] = nFileLength; ;+.cD
} yZN~A:
} `<kB/T
+prUau*
_8!x
//启动子线程 7&9w_iCkV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?rA3<j
for(int i=0;i<nStartPos.length;i++) c&N;r|N
{ Nukyvse
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tfu`_6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b^&azUkMN
nStartPos,nEndPos,i); *l;S"}b*,_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b(CO7/e>
fileSplitterFetch.start(); #oR`_Dm)P
} g"k4Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a 9{:ot8,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `SOQPAnK+;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^*.+4iHx
nEndPos = " + nFileLength); 4HR36=E6
// fileSplitterFetch[nPos.length-1].start(); ![nL/
G.^)5!By
'2hy%
//等待子线程结束 mRm}7p
//int count = 0; (wuciKQ
//是否结束while循环 c~O Lr
boolean breakWhile = false; Tl'wA^~H
4/k`gT4
D~BL Txq
while(!bStop) FRajo~H
{ 8|<</v8i
write_nPos(); MnZljB
Utility.sleep(500); )Tp"l"(G
breakWhile = true; 7(uz*~Z?`0
S89j:KRXH%
vd(S&&]o1
for(int i=0;i<nStartPos.length;i++) Jwfb%Xge~
{ 9<&M~(dwT4
if(!fileSplitterFetch.bDownOver) M. % p'^5
{ @/|g|4
breakWhile = false; 4}k@p>5v'
break; aL*MCgb'
} %OB>FY:|
} F8dr-"G
if(breakWhile) Du65>O
break; =}kISh
5>+@.hPX
r~YBj>}
//count++; 4H%#Sn#L^!
//if(count>4) &M<"Fmn
// siteStop(); H#D:'B j29
} :9ia|lN
D_0sXIbg
)W>$_QxbN
System.err.println("文件下载结束！"); egSs=\
} j5" L
catch(Exception e){e.printStackTrace ();} A{J?I:
} mRRZ/m?A(
E:B"!Y6
Y'~O_coG
//获得文件长度 m BFNg3_
public long getFileSize() Anu:
{ Khi;2{`
int nFileLength = -1; t0e5L{ QJ
try{ _s#]WyU1g
URL url = new URL(siteInfoBean.getSSiteURL()); %(p9AE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )mf|3/o
httpConnection.setRequestProperty("User-Agent","NetFox"); R&;x_4dr^
nRB3VsL
&'&)E((
int responseCode=httpConnection.getResponseCode(); mj e9i
if(responseCode>=400) K mH))LIv
{ k<Gmb~Tg1
processErrorCode(responseCode); .=Oww
return -2; //-2 represent access is error EjFpQ|-L|
} P?f${t+
><D2of|
YR0AI l:L
String sHeader; au+Jz_$)
>I5Wf/$
1!G}*38;
for(int i=1;;i++) HQ9tvSc
{ h[iO'Vq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vJGH8$%;,
//Utility.log(in.readLine()); -O?HfQ
sHeader=httpConnection.getHeaderFieldKey(i); ]58~b%s
if(sHeader!=null) !`H{jwH
{ PkyX,mr#1
if(sHeader.equals("Content-Length")) OYt_i'Q
{ =,;$d&#*h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ejyx[CF
break; EGqu-WBS
} )#M$ov
} %i3[x.M
else X$\CC18
break; 8%u|[Si;
} 6M7GPHah
} TA/hj>rV
catch(IOException e){e.printStackTrace ();} YYFS ({
catch(Exception e){e.printStackTrace ();} n:wAxU
i0wBZ i?
u;H^4} OQ
Utility.log(nFileLength); dtY8>klI
+u=VO#IA#
!2HF|x$
return nFileLength; 5lD`qY
} K<::M3eQ
j*|0#q;e6
am3.Dt2\
//保存下载信息（文件指针位置） G)[gLD{g?
private void write_nPos() 6c(b*o
{ =J)-#|eZG
try{ ,7s+-sRG
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^pu8\K;~
output.writeInt(nStartPos.length); PR!0=E*}
for(int i=0;i<nStartPos.length;i++) x?B`p"ifS
{ v)O].Hd
// output.writeLong(nPos); n(#yGzq
output.writeLong(fileSplitterFetch.nStartPos); }z/%b<o_
output.writeLong(fileSplitterFetch.nEndPos); CfS;F
} vv2[t
output.close(); ^4,LIIUj
} >r(`4M:
catch(IOException e){e.printStackTrace ();} ndDF(qHr
catch(Exception e){e.printStackTrace ();} G#`
} gV9bt~
'j{o!T0
w{_g"X
//读取保存的下载信息（文件指针位置） NQuqM`LSQ
private void read_nPos() T zS?WYF
{ 0/|Ax-dK
try{ p`\>GWuT!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o[eZ"}~
int nCount = input.readInt(); P"}"q ![
nStartPos = new long[nCount]; F?FfRzZ[
nEndPos = new long[nCount]; XefmC6X
for(int i=0;i<nStartPos.length;i++) lcEK&AtK
{ 3rHn?
nStartPos = input.readLong(); hg<[@Q%$o
nEndPos = input.readLong(); ; }T+ImjA
} KrG,T5
input.close(); cVMRSp
} >L "+8N6
catch(IOException e){e.printStackTrace ();} FAc^[~E
catch(Exception e){e.printStackTrace ();} hW!n"qU
} aY.cx1"
P'}B5I~
stW G`>X
private void processErrorCode(int nErrorCode) ='+I dn#5
{ -(lP8Y~gFY
System.err.println("Error Code : " + nErrorCode); 9I<~t@q5e@
} >/ A'G
m`$Q/SyvG
0,@^<G8?
//停止文件下载 u&TXN;I,p
public void siteStop() b3 =Z~iLv
{ !J@!2S9
bStop = true; b]xoXC6@t
for(int i=0;i<nStartPos.length;i++) [iO8R-N8d
fileSplitterFetch.splitterStop(); kQd|qZ=:w
/|H9Gm
^LB]
} %*Mr ^=
} :Ru8Nm
//负责部分文件的抓取 +zLw%WD[l
**FileSplitterFetch.java n=$ne2/
*/ KDGrX[L:6
package NetFox; J}8p}8eF,
"zXrfn
rMjb,2*rC7
import java.io.*; )Qe]!$tqfD
import java.net.*; `T1bY9O.
{5c?_U
2.MUQ;OX
public class FileSplitterFetch extends Thread { BgdUG:;&
* ]bB7
J#i7'9g
String sURL; //File URL A! HJ
long nStartPos; //File Snippet Start Position cbm;45 L|
long nEndPos; //File Snippet End Position puWMgvv
int nThreadID; //Thread's ID (>x05nh
boolean bDownOver = false; //Downing is over mDbTOtD
boolean bStop = false; //Stop identical Z^4+ 88
FileAccessI fileAccessI = null; //File Access interface +'olC^?5 }
5}]+|d;
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NR k~
{ > 3(,s^
this.sURL = sURL; oZ tCx
this.nStartPos = nStart; ceCO*m~
this.nEndPos = nEnd; zG9D Ph
nThreadID = id; Rj>A",
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q#qfuwz
} 2?Jw0Wq5D
qsbo"29
;A7JX:*?y=
public void run() \**j\m
{ A]i!131{w|
while(nStartPos < nEndPos && !bStop) i}v.x
{ g<0K i^#
4\v &8">LL
leH7II9
try{ 6G"UXNa,
URL url = new URL(sURL); eh]syeKBj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g.hYhg'KUh
httpConnection.setRequestProperty("User-Agent","NetFox"); y1PyH
String sProperty = "bytes="+nStartPos+"-"; w"dKOdY
httpConnection.setRequestProperty("RANGE",sProperty); e_KfnPY
Utility.log(sProperty); Jx}-Y* o
C:5d/9k
Lkx~>U
InputStream input = httpConnection.getInputStream(); c};%VB
//logResponseHead(httpConnection); YOGj__:
+M_ _\7
_&S#;ni\c
byte[] b = new byte[1024]; { ,c*OR
int nRead; _~\} fY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `m<O!I"A
{ `kQosQV
nStartPos += fileAccessI.write(b,0,nRead); J-dB
//if(nThreadID == 1) AzXLlQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1@KiP`DA
} >Q=^X3to
XJ3sqcS
breF,d$
Utility.log("Thread " + nThreadID + " is over!"); QNU~G3
bDownOver = true; msfE;
//nPos = fileAccessI.write (b,0,nRead); YuknZ&Q
} LPJ7V`!k
catch(Exception e){e.printStackTrace ();} FV "pJ
} HV/:OCK
} U6@c)_* <
|>]@w\]
r\ft{Z<P
//打印回应的头信息 yFDeYPZP
public void logResponseHead(HttpURLConnection con) mWaij]1>
{ Ri"hU/H{
for(int i=1;;i++) LiT%d
{ >rEZ$h
String header=con.getHeaderFieldKey(i); Sf*v#?
if(header!=null) \'j(@b,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z@+nkTJ9&t
Utility.log(header+" : "+con.getHeaderField(header)); A3_p*n@
else zQY ,}a
break; /ie&uWy
} k"i3$^v8
} m- <y|3
K}@rte
!9/`PcNIpy
public void splitterStop() +8//mrL_/
{ ^{MqJ\S7H
bStop = true; 4DCh+|r
} lgU!D |v
xE<H@@w
E! NtD).=S
} Gr2}N"X=
,6g{-r-2
(X"5x]7]
/* "crR{OjE"
**FileAccess.java 9#:nlu9
*//文件访问(定位，写) ?Cf'IBpN
package NetFox; ?;W"=I*3
import java.io.*; d5gwc5X
La1:WYt
_j, Tc*T
public class FileAccessI implements Serializable{ [#gm[@d,
PDD2ouv4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l.pxDMY
RandomAccessFile oSavedFile; VX.LL 5
long nPos; &EV%g6
YM_[
fW2NYQP$:
public FileAccessI() throws IOException o!UB x<4
{ 2: gh q
this("",0); G)<B7-72;
} h7E?7nR
:.g/=Q(T~
]j7`3%4uK
public FileAccessI(String sName,long nPos) throws IOException &qXobJRM
{ OoA!N-Q
oSavedFile = new RandomAccessFile(sName,"rw"); S&UP;oc
this.nPos = nPos; rogy`mh\r2
oSavedFile.seek(nPos); jnp~ACN,
} O.Pp*sQ^
n+=qT$w)
%W D^0U|
public synchronized int write(byte[] b,int nStart,int nLen) .c]>*/(+
{ 1<m`38'
int n = -1; GZaB z#U
try{ tjThQ
oSavedFile.write(b,nStart,nLen); Fj<*!J$,
n = nLen; +g?uvXC&
} ?X|q
catch(IOException e) $BehU
{ -b!Z(}JK
e.printStackTrace (); VCc=dME
} 7#j.yf4
k ?KJ8
=|AYT6z,
return n; k#pO+[ x
} If'2 m_
B\R X
1#3|PA#>
} (^iF)z
RP{0+
0e0)1;t\
/* ~-vCY
**SiteInfoBean.java A3tv'-e9
*/ b|.Cqsb
package NetFox; O#;sY`fy_M
f$^wu~
w.58=Pr
public class SiteInfoBean { O'(Us!aq
;8PO}{rD
RN 4?]8
private String sSiteURL; //Site's URL %`k [xz
private String sFilePath; //Saved File's Path &G_#=t&
private String sFileName; //Saved File's Name :y7K3:d3
private int nSplitter; //Count of Splited Downloading File !dwZ`D
M>5OC)E
|*JMPg?zI
public SiteInfoBean() hO[_ _j8
{//nSplitter的缺省值为5 KE"6I
//default value of nSplitter is 5 AJ6l#j-
this("","","",5); ?xv."I%
} TO89;O
(U#,;
nuWQ3w p[e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) wi+Qlf
{ ?3K~4-!?/
sSiteURL= sURL; tf7HhOCYX
sFilePath = sPath; [ x+-N7
sFileName = sName; ]@Y!,bw&
this.nSplitter = nSpiltter; Wap4:wT
'gor*-o:wu
7xO05)bz
} ^_3Ey
x[};x;[ZE
*cM=>3ws/
public String getSSiteURL() 75p9_)>96
{ \Y"S4<"R
return sSiteURL; %T>@Ldt
} I~F&@
iCpm^XT
|MKR&%Na
public void setSSiteURL(String value) ;taZixOH
{ 7.VP7;jys
sSiteURL = value; VRY(@# q
} |DW^bv
XdDQ$'*X
CC!`fX6z>h
public String getSFilePath() PTe$dPB
{ 3HXeBW
return sFilePath; Eh;Ia6}
} V0m1>{
<-N eusx%
p'^}J$
public void setSFilePath(String value) j%3$ytf|p
{ ESoqmCJjb:
sFilePath = value; yxx_%9X
} Bn8&~
W20- oZ8
>.P*lT
public String getSFileName() n1|]ji[c
{ l+6@,TY1U
return sFileName; M6MxY\uM
} o/,%rA4
,e$RvFB
D_<B^3w)
public void setSFileName(String value) yD3vq}U!
{ sCy.i/y
sFileName = value; Bz,D4E$
} O<!^^7/h0
6C.!+km
nUONI+6Z/
public int getNSplitter() |af<2(d
{ PNLlJlYlP
return nSplitter; YVRE9
} w0js_P-uv
4ybOK~z
$(J)F-DB i
public void setNSplitter(int nCount) _kOuD}_|
{ Y uZ
nSplitter = nCount; 9|>y[i
} jj `0w@
} 7je1vNs
c?xeBC1-
P'_ aNU
/* {XhpxJ__
**Utility.java VasQ/
*/ Dh{P23}
package NetFox; :1iXBG\
. VI #
~c1~)QzZ
public class Utility { /KvpJ4
a3Z()|t>
jAt65a
public Utility() n!b*GXb\
{ mn<ea&
&:+_{nc,
rUiUv(q
} _x#r,1V+D
~ C_2D?
//线程睡眠 4f0dc\$
public static void sleep(int nSecond) '?fn} V
{ 78b9Sdi&
try{ &zP\K~Nt
Thread.sleep(nSecond); tK <)A)
} KRcg
catch(Exception e) v#IZSBvuQK
{ `+r5I5
e.printStackTrace (); IZ4jFgpR
} 8J9o$Se
} R?%|RCht1
inGH'nl_
//日志 ~u-`L+G"6
public static void log(String sMsg) h"nv[0!)
{ 0$nJd_gW_
System.err.println(sMsg); U`'w{~"D%
} CV7.hF<
z!j`Qoh?V9
WHF:>0B
public static void log(int sMsg) }KkH7XksF
{ F{<rIR
System.err.println(sMsg); }@A~a`9g
} .~8IW,[
} :Ws3+OI'm3
Nb{oH+$b
qm}7w3I^
/* 55|$Imnf
**TestMethod.java g(;ejKSR
*/ N=L urXv
package NetFox; 7~`6~qg.
17qrBG-/MD
ck<4_?1]
public class TestMethod { K<_H`k*x
;6)|'3.B9
CnA*o 8w
public TestMethod() 7y`~T+
{ ///xx/weblogic60b2_win.exe &c@I4RV|q
try{ ZNA?`Z)f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p|bpE F=U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +Q_Gm3^
SiteFileFetch fileFetch = new SiteFileFetch(bean); L_Ai/'
fileFetch.start(); Ri-wbYFaP
} $S cjEG:6
catch(Exception e){e.printStackTrace ();} ->#7_W
@o^sp|k !
"|&*MjwN6
} XJ NKM~
C,z]q$4
YGn:_9
public static void main(String[] args) F;NZJEy
{ ,zyrBO0 Eq
new TestMethod(); bo"I:)n;
} IH0^*f
} 9VY_gi=vL
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