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)); ~Mv@Bl
} 'hl>pso.
for(int i=0;i<nEndPos.length-1;i++) L&1VPli
{ z\Y+5<a
nEndPos = nStartPos[i+1]; e{edI{g
} ]KGLJ~hm>
nEndPos[nEndPos.length-1] = nFileLength; nG;wQvc
} JZp*"UzQr
} ?45kN=%*s
\14"Bgj1
$AAv%v
//启动子线程 DSY:aD!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OYGh!sW
for(int i=0;i<nStartPos.length;i++) 37)Dx
{ LTu cs}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P&3'N~k-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VOBzB]
nStartPos,nEndPos,i); "J]_B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eR r.j
fileSplitterFetch.start(); .5I!h !
} }7CMXw [
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ` bd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~YHy'.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y:C7S~
nEndPos = " + nFileLength); >W"gr]R<
// fileSplitterFetch[nPos.length-1].start(); H4LZNko
O=}4?Xv
O"4Q=~Y
//等待子线程结束 )/H=m7}1h
//int count = 0; _[-+%RP
//是否结束while循环 ]gYnw;W$
boolean breakWhile = false; >N>WOLbb7(
U'S}7gya
M:|Z3p K
while(!bStop) "bAkS}(hB(
{ )xiiTkJd5
write_nPos(); _^Lv8a3(O
Utility.sleep(500); <A&mc,kj
breakWhile = true; >*H>'O4
8DbXv~3@
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for(int i=0;i<nStartPos.length;i++) -x2/y:q`
{ zVe@`gc
if(!fileSplitterFetch.bDownOver) b:/;
{ !YL|R[nDH|
breakWhile = false; 7''l\3mIn
break; 2?ac\c6"
} ~H/|J^ J
} 78>)<$+d
if(breakWhile) c%v[p8 %
break; jq#_*&Eg]
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zu&5[XL
//count++; X-9>;Mb~y
//if(count>4) H];|<G
// siteStop(); f>ohu^bd
} mh]'/C_*<w
Rkm1fYf
V0 x[sEW
System.err.println("文件下载结束！"); $.kP7!`:,
} %se4aeOrX
catch(Exception e){e.printStackTrace ();} ![3#([>4>
} 9tsI1]1[m
)ALPMmlRs
`,d*>
//获得文件长度 SV16]Vc
public long getFileSize() B PTQm4TN
{ &Yi)|TU3'R
int nFileLength = -1; q}>1Rr|U`
try{ M3@Wb@
URL url = new URL(siteInfoBean.getSSiteURL()); jW*|Mu>2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9Y!N\-x`
httpConnection.setRequestProperty("User-Agent","NetFox"); yjUZ40Dq
\#.,@g
5G=<2;
int responseCode=httpConnection.getResponseCode(); py.lGywb_
if(responseCode>=400) [2#5;')
{ K,e"@G
processErrorCode(responseCode); ){`s&?M0
return -2; //-2 represent access is error ;EbGW&T
} Gm;)Om_
Vy0s%k
sm5\> L3V
String sHeader; t!RR5!
{'VP_ZS1v
zY~
for(int i=1;;i++) _O)xE9t#ru
{ z(2pl}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B*7Y5_N
//Utility.log(in.readLine()); RY'f%c
sHeader=httpConnection.getHeaderFieldKey(i); b/'{6zn
if(sHeader!=null) =!T@'P?
{ `s5<PCq
if(sHeader.equals("Content-Length")) H"czF
{ u~n*P``{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,T@+QXh
break; pSp/Qpb-B
} f =@'F=
} 1=(jpy
else g^|}e?
break; sC >_ulkoa
} |U{9Yy6p
} c'cK+32
catch(IOException e){e.printStackTrace ();} ^hq+ L^$^
catch(Exception e){e.printStackTrace ();} 0/K?'&$yvb
(5- w>(
HS>(y2}'
Utility.log(nFileLength); :T^!<W4
2N*XzVplN
e??tp]PLn
return nFileLength; )!6JSMS
} Uytq,3Gj6
kFKc9}7W
9U[Gh97Sf
//保存下载信息（文件指针位置） \kSoDY`l&
private void write_nPos() iV9wqUkMv
{ .T~<[0Ex+U
try{ ZK:dhwer
output = new DataOutputStream(new FileOutputStream(tmpFile)); X&C&DTB
output.writeInt(nStartPos.length); 1Q_ C
for(int i=0;i<nStartPos.length;i++) TdGda'C
{ A/5??3H
// output.writeLong(nPos); 8Aq [@i
output.writeLong(fileSplitterFetch.nStartPos); S1jI8 #z}_
output.writeLong(fileSplitterFetch.nEndPos); 1B}q?8n
} ?%RAX CK
output.close(); PJd7t%m;
} $ti*I;)h4
catch(IOException e){e.printStackTrace ();} n(X{|?
catch(Exception e){e.printStackTrace ();} 6 3TeTGp$
} Xae0xs
GMk\ l
5\\#kjjx
//读取保存的下载信息（文件指针位置） ggluQGA
private void read_nPos() B$A`thQp
{ mL5Nu+#
try{ C]@v60I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7 s+j)
int nCount = input.readInt(); Za,MzKd=
nStartPos = new long[nCount]; hz:^3F`>/&
nEndPos = new long[nCount]; Q1ox<-
for(int i=0;i<nStartPos.length;i++) g)Ep'd-w"
{ @ P:b\WCI
nStartPos = input.readLong(); 4Vv~
nEndPos = input.readLong(); L >* F8|g
} rw CFt6;v
input.close(); 3k%fY
} Iw07P2
catch(IOException e){e.printStackTrace ();} ? PIq/[tk
catch(Exception e){e.printStackTrace ();} O &/9wi>!q
} gK&MdF*
U,G!u=+
JA=9EnTU
private void processErrorCode(int nErrorCode) N+)gYb6h
{ #9R[%R7Nz
System.err.println("Error Code : " + nErrorCode); iCz0T,
} 1/ZvcdYB
R1!F mZW8
.,-,@ZK
//停止文件下载 S%NS7$`a
public void siteStop() E$u9Jbe
{ +2DzX/3
bStop = true; 7m4gGkX#r
for(int i=0;i<nStartPos.length;i++) dwH8Zg$B
fileSplitterFetch.splitterStop(); $0-}|u]5U
?MW*`U
TO(2n8'fdO
} nZ4JI+Q)~
} Dw%V.J/&o
//负责部分文件的抓取 |JUb 1|gi
**FileSplitterFetch.java y v$@i A
*/ /.knZ_aJ!
package NetFox; ZWtlOP#]
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3SI~?&HU!/
import java.io.*; A#b`{C~l
import java.net.*; \n&l
pBZf=!+E
"e3T;M+
public class FileSplitterFetch extends Thread { ZqDanDM
%OV)O-
B-R& v8F
String sURL; //File URL IIZu&iZo\
long nStartPos; //File Snippet Start Position cC4 2b2+
long nEndPos; //File Snippet End Position {?!0<0
int nThreadID; //Thread's ID a>05Yxw
boolean bDownOver = false; //Downing is over M1Frn n
boolean bStop = false; //Stop identical 3 L:s5
FileAccessI fileAccessI = null; //File Access interface %',bCd{QW
o4[
(Yv)%2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V(?PKb-w)
{ KTmduf7DL
this.sURL = sURL; 2!w5eWl,
this.nStartPos = nStart; 1#Ls4+]5
this.nEndPos = nEnd; 0\y{/P?I$
nThreadID = id; Vgj&hdbd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dj;Zzt3
} \ZOH3`vq
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G\;a_]Q
public void run() 9B&fEmgEc?
{ sOf;I]E|
while(nStartPos < nEndPos && !bStop) pBbfU2p
{ ZaZm$.s n
i3SrsVSG
liuw!
try{ NI%&Xhn!*>
URL url = new URL(sURL); ;1^([>|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zK_+UT
httpConnection.setRequestProperty("User-Agent","NetFox"); rgK:ujzW!
String sProperty = "bytes="+nStartPos+"-"; oPbxe
httpConnection.setRequestProperty("RANGE",sProperty); -".q=$f
Utility.log(sProperty); f6*6*=
c@&`!e
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InputStream input = httpConnection.getInputStream(); lG>,&(
//logResponseHead(httpConnection); eF06B'uL
}j_2K1NS{
Rt6(y #dF
byte[] b = new byte[1024]; *URBx"5XZ
int nRead; +%'!+r l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %Ums'<xJ
{ e{}oQK
nStartPos += fileAccessI.write(b,0,nRead); ALO0yc
//if(nThreadID == 1) }iE!( l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <pXF$a:s
} Ht,dMt>:
"N*bV
<8,,pOb
Utility.log("Thread " + nThreadID + " is over!"); ~w,c6Z
bDownOver = true; |}07tUq
//nPos = fileAccessI.write (b,0,nRead); pFW^
} EG&97lb
catch(Exception e){e.printStackTrace ();} PCkQ hR
} Xk]:]pl4W
} t~0!K;nn
+k<0:Fi
7/>#yR
//打印回应的头信息 G<_<j}=
public void logResponseHead(HttpURLConnection con) Ui43&B
{ W-8U~*/
for(int i=1;;i++) }Tz<fd/
{ Gdu5 &]H#6
String header=con.getHeaderFieldKey(i); ,ej89
if(header!=null) ~_GW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %={[e`,
Utility.log(header+" : "+con.getHeaderField(header)); .VG5 / 6zp
else M}Obvl
break; H~ `JAplr
} xJ(}?0h-X
} XN Gw@$
,VYUQE>\
0Uf.aP
public void splitterStop() D9 \!97
{ B ?%g@d-;
bStop = true; "+sl(A3`U
} 6Qw5_V^0o
P~^VLnw
bSvr8FY3d
} D~T;z pS
q?0&&"T}
- xE%`X
/* 5oTj^W8M(
**FileAccess.java $O[$<D%H
*//文件访问(定位，写) ]; Z[V
package NetFox; G}V5PEF]`
import java.io.*; dVKctt'C
/JGET
SsBiCctn
public class FileAccessI implements Serializable{ $TZjSZ1w
dc=}c/6x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /!A?>#O&.
RandomAccessFile oSavedFile; Bbj%RF2,
long nPos; O =gv2e
MY w3+B+Jj
<nk7vo?Ks
public FileAccessI() throws IOException /3KPK4!m
{ (`)ZR%i
this("",0); {^*K@c
} x"83[0ib
T)lkT?
w,!IvDCAw
public FileAccessI(String sName,long nPos) throws IOException oU)Hco"_k
{ h6;vOd~%
oSavedFile = new RandomAccessFile(sName,"rw"); d9Uv/VGp
this.nPos = nPos; k%Wj+\93f
oSavedFile.seek(nPos); e$l*s/"0t
} ^hRx{A
!L3\B_#
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public synchronized int write(byte[] b,int nStart,int nLen) uFYcVvbT@
{ zXZXp~7)
int n = -1; wmDO^}>ZP
try{ 12o6KVV^x
oSavedFile.write(b,nStart,nLen); iPCDxDLN3V
n = nLen; 1haNpLfS>
} 3k# h!Z
catch(IOException e) yB5JvD ?
{ t b>At*tO
e.printStackTrace (); r0/aw
} wB+X@AA
xRbtiFk9H
rr^?9M*{V
return n; pB:/oHV
} z2U^z*n{
3,yzRb
g@|2z
} Px?zih!6
FjV)QP H
oxNQNJ!X
/* ;:1o|>mX
**SiteInfoBean.java C+%6N@
*/ *X\J[$!
package NetFox; NnRX0]
k*K.ZS688
a)QSq<2*
public class SiteInfoBean { +!cibTQTT
ZtGtJV"H
S0w:R:q}L
private String sSiteURL; //Site's URL g+]o=@
private String sFilePath; //Saved File's Path \rM5@ Vf
private String sFileName; //Saved File's Name R q`j|tY
private int nSplitter; //Count of Splited Downloading File 61Wh %8-
Sf'uKSX1%
jidRh}>a=
public SiteInfoBean() yrG=2{I
{//nSplitter的缺省值为5 ZVz`g]
//default value of nSplitter is 5 _sK{qQxvM=
this("","","",5); |_mN:(3
} 2= zw!
@tlWyUju
)x3p7t)#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |f3 :9(p
{ 6,~]2H'zq
sSiteURL= sURL; H>F j
sFilePath = sPath; p:zRgwcn
sFileName = sName; heScIe N^`
this.nSplitter = nSpiltter; X16vvsjw5
u]Z;Q_=
\Vx_$E
} H;MyT Vl
r"!xI
%5!K?,z%
public String getSSiteURL() @?*; -]#)
{ ,</Kn~b
return sSiteURL; g(dReC
} ) uTFId
*iVEO
)]C(NTfxg
public void setSSiteURL(String value) NqM=Nu\
{ 9qvl9,*g
sSiteURL = value; uM,R+)3
} 1s.>_
dOVu D(
V[0 ZNT&
public String getSFilePath() 6w~Cyu4Ov
{ [l}H%S
return sFilePath; $f=6>Kn|^]
} dF><XZph
>qZl s'
aU*}.{<!
public void setSFilePath(String value) w+$~ds
{ &WZ&Tt/)/
sFilePath = value; .'NTy R
} )Em`kle
MzH'<`;BP
-vv_6ZL[
public String getSFileName() 0i>p1/kv
{ intl?&wC
return sFileName; }Fsr"RER@{
} 5\}E4y
@VQ<X4Za
L{oG'aK4
public void setSFileName(String value) _9'hmej
{ [5]n,toAh
sFileName = value; "R"{xOQl
} biV NZdA
7CH.BY
I&`aGnr^^
public int getNSplitter() _bt9{@)
{ frc9
return nSplitter; /vC!__K9:
} 7Ah
]Ljb&*IEj
x_CY`Y
public void setNSplitter(int nCount) YFDOp*
{ R{ udV
nSplitter = nCount; 1Vc~Sa
} o]]sm}3N
} hM[3l1o{|
w[$oH^7
w|Ry)[
/* UyFC\vQ
**Utility.java Ow(aRWUZD_
*/ 7!wc'~;
package NetFox; 3D^cPkX
Uf MQ?(,
\XwC|[%P
public class Utility { +o):grWvQ
s6r(\L_Im
q|0l>DPRp
public Utility() hA;Ai:8
{ [!MS1vc;
sPVE_n
|3 Iug
} 'oH3|
e-OKv#]
//线程睡眠 IZ\fvYp
public static void sleep(int nSecond) A3*(c3
{ gf?N(,
try{ f:y1eLl3
Thread.sleep(nSecond); zR<fz
} z 2jC48~
catch(Exception e) k"C'8<T)'
{ y?P`vHf
e.printStackTrace (); ^b}Wl0Fn
} z&Aya*0v`
} MT:VQ>fC
sOiM/}O]
//日志 rV4K@)~
public static void log(String sMsg) <=D a
{ G "!v)o
System.err.println(sMsg); -(>Ch>O
} KV$4}{
I8`$a
ipl,{
public static void log(int sMsg) $45.*>,
{ ;ISe@yR;
System.err.println(sMsg); ZO%iyc%
} A0U9,M
} U*E)y7MY
,G5[?H;ZN
yP>025o't
/* 7S&$M-k
**TestMethod.java 3-,W? "aC
*/ 2%6 >)|
package NetFox; gzqp=I[%
y Vm>Pj6
-{8K/!
public class TestMethod { %+Y wzL{
y1T(R#
CaO-aL
public TestMethod() q<!-Anc
{ ///xx/weblogic60b2_win.exe tq3Rc}
try{ *8m['$oyV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EwU)(UK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +xU({/
SiteFileFetch fileFetch = new SiteFileFetch(bean); c-}[v<o
fileFetch.start(); pMy:h
} =-X-${/
catch(Exception e){e.printStackTrace ();} s.Bb@Jq
3l41"5Fy&
3 V>$H\H
} rF"p7
h~](9es
KR%WBvv
public static void main(String[] args) V+y"L>K
{ x: _[R{B
new TestMethod(); &KAe+~aPm
} qy)~OBY
} mfaU_Vo&
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