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)); b2C`g]ibQ
} M.q=p[
for(int i=0;i<nEndPos.length-1;i++) 2%B'3>a
{ -WJ?:?'
nEndPos = nStartPos[i+1]; (MLwQiop
} Y?d9l
nEndPos[nEndPos.length-1] = nFileLength; hK|j6xf.o
} x/ *-P b-_
} \ZI'|Ad
;# uZhd
?D`T7KSe~D
//启动子线程 ?6^|ZtB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7zemr>sIh
for(int i=0;i<nStartPos.length;i++) W-efv
{ UUc8*yU)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?jx1R^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0Ua%DyJ
nStartPos,nEndPos,i); >&:NFq-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )%d*3\Tsd
fileSplitterFetch.start(); PG~$D];
} a<~77~"4wn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eHiy,IN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 47K1$3P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9(4&KZpK
nEndPos = " + nFileLength); R?o$Y6}5
// fileSplitterFetch[nPos.length-1].start(); nkfZiyx
eWJ`$"z
*{ {b~$
//等待子线程结束 kM8{Cw
//int count = 0; v\tEVhm
//是否结束while循环 g%[c<l9
boolean breakWhile = false; #_93f |
06q(aI^Ch@
-G7TEq)
while(!bStop) s$D ^>0
{ 7*5Z
write_nPos(); Jg}K.1Hs
Utility.sleep(500); BZ!v%4^9
breakWhile = true; ;!!n{l$r'
(xHf4[[u
h:Gu`+D>W
for(int i=0;i<nStartPos.length;i++) z`UhB%-?
{ :a ->0 l
if(!fileSplitterFetch.bDownOver) pi<TFe@eG
{ 2;a(8^n
breakWhile = false; jRSUp E8
break; +ZM)bbB
} ="wzq+U
} y*pUlts<
if(breakWhile) i.D3'l
break; aI^/X{d
nw>8GivO
9RN-suE[
//count++; (0YZZ93
//if(count>4) /='. 4v
// siteStop(); InXn%9]p]
} VXIP0p@
2EZb )&Q
Y2o?gug
System.err.println("文件下载结束！"); 3b'QLfU&#
} m< _S_c
catch(Exception e){e.printStackTrace ();} 3 @ak<9&
} 'u4<BQVV[
;s`sn$@
ks$JP6
//获得文件长度 pn.wud}R
public long getFileSize() MjlP+; !
{ $YN6<5R)
int nFileLength = -1; $hivlI-7Ko
try{ )OiT{-m
URL url = new URL(siteInfoBean.getSSiteURL()); b2b^1{@h;v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o(DOQGl
httpConnection.setRequestProperty("User-Agent","NetFox"); h 3]wL.V
S;$-''o?9
[<DZ*|+
int responseCode=httpConnection.getResponseCode(); KD`IX-r{s
if(responseCode>=400) &l3iV88
{ Oo"^%F~%
processErrorCode(responseCode); KMI_zhyB
return -2; //-2 represent access is error 0"CG7Vg,zh
} .pvi!NnL-
&?mD$Eo
Tyvtmx M
String sHeader; ,lZB96r0
,AxdCT
_%5Ro6
for(int i=1;;i++) ]]Cb$$Td
{ )+:EJH~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $5Xh,DOg
//Utility.log(in.readLine()); C(00<~JC
sHeader=httpConnection.getHeaderFieldKey(i); S30?VG9U0f
if(sHeader!=null) $2W%2rZ
{ (p2K36,9m
if(sHeader.equals("Content-Length")) :xtXQza"-
{ :yUEkm8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N5a*7EJv+
break; ?OkWe<:4
} sBr_a5QQ#
} a)wJT`xu
else ,%uo6%
break; eeyHy"@
} "?V0$-DR
} |&RU/a
catch(IOException e){e.printStackTrace ();} &YF^j2
catch(Exception e){e.printStackTrace ();} 1v71rf&w
"rx-_uK*
O^oWG&Y;v
Utility.log(nFileLength); mV3cp rRqv
O8h%3&
V5UF3'3;}
return nFileLength; ["h5!vj
} ogyTO|V=
Vh_P/C+
9I}-[|`u
//保存下载信息（文件指针位置） ,6-:VIHQ
private void write_nPos() Wk)OkIFR
{ \O2Rhz
try{ #"@|f
output = new DataOutputStream(new FileOutputStream(tmpFile)); *MKO I'
output.writeInt(nStartPos.length); L7dd(^
for(int i=0;i<nStartPos.length;i++) o,_?^'@
{ n*2UnKaJ
// output.writeLong(nPos); JpXlBEio%
output.writeLong(fileSplitterFetch.nStartPos); Xu%'Z".>:
output.writeLong(fileSplitterFetch.nEndPos); MF5[lK9e
} >m$1Xx4#GV
output.close(); G3Z)Z)N
} %J+E/
catch(IOException e){e.printStackTrace ();} KrQ1GepJ
catch(Exception e){e.printStackTrace ();} #1OOU
} e)d`pQ6
<g$~1fa
'@_d(N1jTw
//读取保存的下载信息（文件指针位置） |olA9mp|]
private void read_nPos() nAv#?1cjz
{ aDU<wxnSvO
try{ 37s0e;aF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,J+}rPe"sf
int nCount = input.readInt(); 'uBu6G
nStartPos = new long[nCount]; 4y|BOVl
nEndPos = new long[nCount]; 'Gj3:-xqL
for(int i=0;i<nStartPos.length;i++) 9Z4nAc
{ RoPRQCE
nStartPos = input.readLong(); 3}}38A|4
nEndPos = input.readLong(); ~E17L]ete
} 6 (]Dh;gC
input.close(); e"|efE
} LRL,m_gt
catch(IOException e){e.printStackTrace ();} VK m&iidU
catch(Exception e){e.printStackTrace ();} pFOx>u2`a
} 0Tx6zO
HiZ*+T.B
Q'=x|K#xj
private void processErrorCode(int nErrorCode) nT7%j{e=L
{ !|^|,"A)
System.err.println("Error Code : " + nErrorCode); T&6l$1J
} 8A##\j)
eA2@Nkw~)
%)1y AdG 8
//停止文件下载 -|$@-fY;
public void siteStop() bCRV\myd`
{ ,E S0NA
bStop = true; C5o#i*|
for(int i=0;i<nStartPos.length;i++) Y]'Z7<U}*E
fileSplitterFetch.splitterStop(); Va"0>KX
*4\:8
;U/&I3dzV
} ]cHgleHQ
} +r2+X:#~T
//负责部分文件的抓取 q'T4w!V(V
**FileSplitterFetch.java >mwlsL~X
*/ e"{{ TcNk
package NetFox; Q /U2^
P3x8UR=fS
gb[5&>(#
import java.io.*; "L IF.)
import java.net.*; 9ijfRqI=x
3lrT3a3vV
W+I!q:p4H
public class FileSplitterFetch extends Thread { em%4Ap
Ni9/}bb
<? q?Mn
String sURL; //File URL ?WGA?J %2
long nStartPos; //File Snippet Start Position %~4M+r6T
long nEndPos; //File Snippet End Position -_=nDH
int nThreadID; //Thread's ID ,LHn90S
boolean bDownOver = false; //Downing is over j'Fpjt"&=
boolean bStop = false; //Stop identical <sb~ ^B
FileAccessI fileAccessI = null; //File Access interface }bb;~
T<n
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $*^7iT4q_t
{ G/)O@Ugp
this.sURL = sURL; '$i: 2mn,
this.nStartPos = nStart; ?1~`*LE
this.nEndPos = nEnd; 03$mYS_?
nThreadID = id; R`NYEptJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KLST\Ln:
} ejSji-Qd
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9 P l
public void run() Kn5~d(:
{ Wf+cDpK
while(nStartPos < nEndPos && !bStop) `KZm0d{H
{ d[iQ`YW5
bV^rsJm
wON!MhA;
try{ /CrSu
URL url = new URL(sURL); uy>q7C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p*XANGA
httpConnection.setRequestProperty("User-Agent","NetFox"); {&&z-^
String sProperty = "bytes="+nStartPos+"-"; ?g_3 [Fk
httpConnection.setRequestProperty("RANGE",sProperty); W: z6Koc0
Utility.log(sProperty); 'TTLo|@"-
\j$&DCv
G<L;4nA)
InputStream input = httpConnection.getInputStream(); yuh *
//logResponseHead(httpConnection); s:n6rG
S\CCrje
?qb}?&1
byte[] b = new byte[1024]; aC]$k'71
int nRead; /2&c$9=1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LQ@"Xe]5
{ ;YaQB#GK%
nStartPos += fileAccessI.write(b,0,nRead); 'p^t^=dQ
//if(nThreadID == 1) \[;0KV_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )*$lp'~7N
} k$n|*kCh
/J]5H
jk;j2YNPw
Utility.log("Thread " + nThreadID + " is over!"); 1.}d.t
bDownOver = true; A @i
//nPos = fileAccessI.write (b,0,nRead); |Tv#4st
} z<MsKD0Q
catch(Exception e){e.printStackTrace ();} 9Gvd&U
} [*Z;\5&P
} lov!o:dJ
(Lbbc+1m
Na<pwC
//打印回应的头信息 xB@ T|EP
public void logResponseHead(HttpURLConnection con) " s,1%Ltt
{ GV1pn) 4
for(int i=1;;i++) esJ~;~[@(r
{ v&6-a*<Z
String header=con.getHeaderFieldKey(i); {y)=eX9
if(header!=null) !Z1@}`V&;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0j^Kgx
Utility.log(header+" : "+con.getHeaderField(header)); B`EJb71^Xy
else Lc}LGq!
break; 9=s<Ld
} ko!)s
} R!HXhQ
lqy Qf$t
y#`tgJ:
public void splitterStop() qv-8)MSr
{ T;4NRC
bStop = true; P?%s #I:
} +5)nk}
9[#pIPxNK
|NlO7aQ>2H
} ~?l | [
+V2F#fI/
\UA[
/* %7hrk
**FileAccess.java Kf3"Wf^q
*//文件访问(定位，写) n3WlZ!$
package NetFox; aHD]k8m z
import java.io.*; )L? P}$+
,Co|-DYf}
ldf\;Qk
public class FileAccessI implements Serializable{ [DuttFX^x
[z:!j$K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &0d#Y]D4`
RandomAccessFile oSavedFile; _T60;ZI+^
long nPos; 'B|JAi?
6%'QjwM_
u*eV@KK!
public FileAccessI() throws IOException ibcRU y0%
{ 0S"mVZ*P
this("",0); hDDn,uzpd
} J4hL_iCQ
fuW\bo3
6bg ;q(*7
public FileAccessI(String sName,long nPos) throws IOException {qk1_yP
{ 7g^]:3f!
oSavedFile = new RandomAccessFile(sName,"rw"); XPc^Tq
this.nPos = nPos; [NTzcSN.
oSavedFile.seek(nPos); : 6jbt:
} ,~U>'&M;
x>K Or,f
1er TldX
public synchronized int write(byte[] b,int nStart,int nLen) G/E+L-N#`
{ KYm0@O>;
int n = -1; p T?}Kc
try{ l$KA)xbI
oSavedFile.write(b,nStart,nLen); <)Dj9' _J
n = nLen; FaAC&F@u
} MpT8" /.]A
catch(IOException e) )$2QZ qX
{ hgG9m[?K
e.printStackTrace (); }FROB/
} r `=I
'@v\{ l
@?sRj&w
return n; %uDi#x.
} gT.sjd
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)_90UwWpj
} zpn9,,~u
,>a&"V^k
fgTg7 m
/* qz_7%c]K[
**SiteInfoBean.java LBeF&sb6
*/ 6q\bB
package NetFox; Pm6pv;WK
K-)] 1BG
M)Z7k/=<P
public class SiteInfoBean { zaIKdI'/e
fUWG*o9
/xBb[44z8
private String sSiteURL; //Site's URL !/b>sN}
private String sFilePath; //Saved File's Path n`_{9R
private String sFileName; //Saved File's Name ,&A7iO
private int nSplitter; //Count of Splited Downloading File dl)Y'DI
mthA4sz
n&4N[Qlv,
public SiteInfoBean() CZwXTHe
{//nSplitter的缺省值为5 XX TL..
//default value of nSplitter is 5 tU5zF.%
this("","","",5); 'ZF{R3Xu
} 4i;{!sT
QE+g j8
1ba~SHi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b~P`qj[
{ { 'eC`04E
sSiteURL= sURL; x;.Jw6g
sFilePath = sPath; VBlYvZ;$*
sFileName = sName; t.y2ff<[U
this.nSplitter = nSpiltter; HVCe;eI
?=msH=N<l
}0*@fO
} L[fiU0^o
9<?M8_
oSKXt}sh
public String getSSiteURL() EWhK0Vej=
{ 9rX&uP)j^#
return sSiteURL; $99n&t$Y
} @gEUm_#HTs
D/gw .XYL
.hb:s,0mP
public void setSSiteURL(String value) G$"h&Xy1c
{ ?4}h&/
sSiteURL = value; xIW3={b3
} 3ZPWze6
sE<V5`Z=
7aRi5
public String getSFilePath() u~:y\/Y6
{ FX&~\kmV'j
return sFilePath; &BLJT9Frx
} 1-uxC^u?|#
76Cl\rV
Ta0|+IYk<
public void setSFilePath(String value) ,-LwtePJ0
{ Rok7n1gW
sFilePath = value; UgSB>V<?
} Xl{P8L
HRCT}
| j`@eF/"
public String getSFileName() 8'[7 )I=
{ -Cpl?Io`r5
return sFileName; eK=xrk
} 49c:V,
M)+H{5bt
/Iy]DU8
public void setSFileName(String value) SM#]H-3
{ !Pvf;rNI1T
sFileName = value; VcYrK4
} gCS<iBT(7
DJ k/{Z:
P )"m0Lu<
public int getNSplitter() 2;`1h[,-^
{ 10~k2{Z
return nSplitter; /9*B)m"
} $9#H04.x
(`>+zT5aH
z, )6"/;
public void setNSplitter(int nCount) 7kLz[N6Ll
{ CyFrb`%
nSplitter = nCount; (Z q/
} jD]~ AwRJ
} N^G Mp,8
J?1 uKR
::lKL
/* wu!59pL
**Utility.java a2O75 kWnm
*/ bHYy}weZ
package NetFox; X/!o\yyT
@f~RdO3
85$m[+md
public class Utility { dr}`H,X"3
x,+{9
|bHelD|
public Utility() .t-4o<7 3
{ TDKki(o=~
6Q@j
G@\1E+Ip
} $y&E(J
".V$~n(
//线程睡眠 k68T`Ub\W6
public static void sleep(int nSecond) K`WywH3-
{ Wx}8T[A}
try{ ;(/ZO%h
Thread.sleep(nSecond); u;"TTN
} &K.d'$q
catch(Exception e) ]L $\ #
{ 3?9IJ5p
e.printStackTrace (); YeL#jtC
} J.b9F:&}
} t;Sb/3
NjScc%@y
//日志 e7Z32P0ls
public static void log(String sMsg) Q7\w+ANf0
{ $\BE&4g
System.err.println(sMsg); S>6~lb8G
} L|:`^M+^w
.-c4wm}
[Cz-i
public static void log(int sMsg) Y@vTaE^w3
{ Nq[uoaT
System.err.println(sMsg); a=9:[
} @7]yl&LZ
} oy=js -
1\~ "VF*{
? 7n`A >T
/* xb~yM%*c
**TestMethod.java cWsNr'MS*
*/ vhW2PzHFRi
package NetFox; Tod&&T'UW
O)*+="Rg
BC#C9|n
public class TestMethod { xp)sBM7A
T{.pM4Hd
XbKYiy
public TestMethod() r&JgLC(
{ ///xx/weblogic60b2_win.exe 4y?n [/M/
try{ u(>^3PJ+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M*, -zGr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !qh]6%l
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,{u yG:
fileFetch.start(); '(f*2eE:
} 8,4"uuI
catch(Exception e){e.printStackTrace ();} #ym'AN
>V?eog%~
-`kW&I0
} iDp)FQ$
eK?MKe
t7Iv?5]N
public static void main(String[] args) HZC"nb}r4
{ v6bGjVK[
new TestMethod(); uK"=i8rs4
} !Vn\u
} ghG**3xr
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