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)); w:/QB-`%
} 2-beq<I
for(int i=0;i<nEndPos.length-1;i++) RSBk^
{ zszx~LSvIT
nEndPos = nStartPos[i+1]; h~s h!W8
} =O>E>Q
nEndPos[nEndPos.length-1] = nFileLength; :Hj #1-U
} `gz/?q
} Xk}\-&C7
i Ie{L-Na
S3ZIC\2
//启动子线程 gXe`G(w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Le*gdoW.
for(int i=0;i<nStartPos.length;i++) Yz? 8n
{ !YIW8SP)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H0-v^H>^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), La r9}nx0
nStartPos,nEndPos,i); SHRn$<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WB3YN+Xl3
fileSplitterFetch.start(); Lc_cB`
} );d"gv(]D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4rUOk"li
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0gH;y+\=*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e@{Rlz
nEndPos = " + nFileLength); #sM*<2vj
// fileSplitterFetch[nPos.length-1].start(); DhN<e7c`
*H~&hs>k
3M5wF6nY[[
//等待子线程结束 I}u&iV`
//int count = 0; Y'76!Y
//是否结束while循环 `_!R;f
boolean breakWhile = false; oW3|b2D
m-lTXA(
<v3pI!)x
while(!bStop) 1@xdzKua1
{ zo:NE00
write_nPos(); o<Qt<*
Utility.sleep(500); Zw_'u=r >
breakWhile = true; naVbcY
F<J`1 :
<jG[ z69)
for(int i=0;i<nStartPos.length;i++) ]MnQ3bWq"j
{ 2k!4oVUN
if(!fileSplitterFetch.bDownOver) f0+vk'Z
{ .zsYVtK
breakWhile = false; W{fNZb'
break; \WxBtpbQB
} nhRpb9f`1@
} "x O+
if(breakWhile) f7:}t+d
break; iJS7g
f0 kz:sZ9
J$i.^|hE/
//count++; C/MQY:X4
//if(count>4) J=b'b%
// siteStop(); R)6"P?h._4
} .+&M,% x
yaPx=^&
WJy\{YAG
System.err.println("文件下载结束！"); j[Gg[7q{y
} |z?c>.
catch(Exception e){e.printStackTrace ();} vQy+^deW
} z/wwe\ a5
3L9@ELY4
}!N/?A5
//获得文件长度 p{AX"|QM"
public long getFileSize() ;*cCaB0u
{ FT\%=>{
int nFileLength = -1; "6gBbm
try{ p\DSFB
URL url = new URL(siteInfoBean.getSSiteURL()); 4@QR2K|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <[?ZpG
httpConnection.setRequestProperty("User-Agent","NetFox"); f([d/
Y(=A HmR
Qcn;:6_&W
int responseCode=httpConnection.getResponseCode(); h!?rk|
if(responseCode>=400) |IDZMd0
{ -Eoq#ULvR
processErrorCode(responseCode); L| ;WE=
return -2; //-2 represent access is error eIQ@){lJ-]
} eU\XAN#@
tgY/8&$M
{RI)I
String sHeader; 1}~`g ED
DB(!*6#?
10^FfwRfM
for(int i=1;;i++) YT6dI"48
{ O]KQ]zN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); slaH2}$xR
//Utility.log(in.readLine()); ~~q>]4>
sHeader=httpConnection.getHeaderFieldKey(i); 38GZ_z}r
if(sHeader!=null) s7,D}Zz
{ 1rON8=E
if(sHeader.equals("Content-Length")) 0cq<!{d
{ z fu)X!t^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U:bnX51D4
break; b4Pa5w
} #3?}MC
} D#gC-,
else klnk{R.>|
break; S|F:[(WaM
} 6zI}?KZf
} /7x1Z*Hg
catch(IOException e){e.printStackTrace ();} gux?P2f
catch(Exception e){e.printStackTrace ();} <`WcI`IAb
d>V#?1$h
F?t;bV
Utility.log(nFileLength); 3Hi8=*
7"1]5\p^g
$g),|[x+(
return nFileLength; \2CEEs'
} Yr[&*>S
i&{%}==7
L_o/fTz4
//保存下载信息（文件指针位置） :*s@L2D6
private void write_nPos() D 9UM8Hxi
{ k 7:Z\RGy
try{ U+zntB
output = new DataOutputStream(new FileOutputStream(tmpFile)); V[n,fEPBr
output.writeInt(nStartPos.length); ja6V*CWb
for(int i=0;i<nStartPos.length;i++) qg:EN~E#
{ sG\K$GP!
// output.writeLong(nPos); u<4bOJn({
output.writeLong(fileSplitterFetch.nStartPos); }}Z2@}
output.writeLong(fileSplitterFetch.nEndPos); j4u ["O3
} | ^G38
output.close(); e;2A{VsD8
} >`p? CE
catch(IOException e){e.printStackTrace ();} MGY0^6yK5
catch(Exception e){e.printStackTrace ();} i!gS]?*DH
} 5vJxhBm/
HiBI0)N}
i.\ e/9]f
//读取保存的下载信息（文件指针位置） iB`EJftI!
private void read_nPos() zrf tF2U
{ _!_1=|[
try{ =2}V=E/85
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zRbY]dW
int nCount = input.readInt(); z#1"0Ks&P
nStartPos = new long[nCount]; 20}w.V
nEndPos = new long[nCount]; {h PB%
for(int i=0;i<nStartPos.length;i++) UZ#oaD8H6
{ Vf<q-3q
nStartPos = input.readLong(); ;e< TEs
nEndPos = input.readLong(); %NM={X|'
} Y[H769
input.close(); M8/:PmR<
} !qU1RdZ
catch(IOException e){e.printStackTrace ();} \+=`o .2
catch(Exception e){e.printStackTrace ();} i<):%[Q)>
} |* ^LsuFb
{ {:Fs
jw`05rw:
private void processErrorCode(int nErrorCode) t=9f:,I$
{ OzwJ 52
System.err.println("Error Code : " + nErrorCode); x,zYNNx5g
} 1vxQ`)a
o\]U;#YD
]^T-X/v9
//停止文件下载 bE{YK
public void siteStop() T]nAz<l),
{ -/V(Z+dj
bStop = true; H5V>d
for(int i=0;i<nStartPos.length;i++) *C<;yPVc
fileSplitterFetch.splitterStop(); >oO]S]W
Z4rk$K'=1w
dfKGO$}V
} Ow.DBL)x'>
} r/HTkXs I
//负责部分文件的抓取 O6vxp?:^
**FileSplitterFetch.java /|<SD.:
*/ jM @N<k
package NetFox; [`s0 L#
R PoBF~>
@0]WMI9B"B
import java.io.*; j/fniyJ)
import java.net.*; fGqX dlP
9t6c*|60#n
RRV%g!
public class FileSplitterFetch extends Thread { 8A.7q
\$*CXjh3G
gPT_}#_GxM
String sURL; //File URL N5,LHO
long nStartPos; //File Snippet Start Position cjJfxD&q
long nEndPos; //File Snippet End Position I:G8B5{J
int nThreadID; //Thread's ID '^>} =f
boolean bDownOver = false; //Downing is over J-<_e??
boolean bStop = false; //Stop identical C\~}ySQc.e
FileAccessI fileAccessI = null; //File Access interface *OznZIn
BAY e:0
I`H&b& .`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8V 4e\q
{ xPPA8~Dm*
this.sURL = sURL; Y0T:%
this.nStartPos = nStart; af %w|M
this.nEndPos = nEnd; AU}kIm_+
nThreadID = id; VsAJ2g9L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d&raHF*
} 5RFro^S9E
o{`x:
1*2ycfa
public void run() CuvY^["
{ XsQ81j.
while(nStartPos < nEndPos && !bStop) EJ#I7_
{ 1n[)({OQ
8.n#@%
vxTn
try{ _:=\h5}8
URL url = new URL(sURL); HbI{Xf[6LP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,;Wm>V)o
httpConnection.setRequestProperty("User-Agent","NetFox"); `bfUP s
String sProperty = "bytes="+nStartPos+"-"; wjwCs`
httpConnection.setRequestProperty("RANGE",sProperty); U4fv$gV
Utility.log(sProperty); 1W{oj
6j XDLI
n:OXv}pv
InputStream input = httpConnection.getInputStream(); GdI,&|/
//logResponseHead(httpConnection); -X!<$<\y;
7@\.()
$"W[e"Q
byte[] b = new byte[1024]; bs?\ )R5/
int nRead; ,v K%e>e&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ">CRFee0
{ m+;U,[%[*E
nStartPos += fileAccessI.write(b,0,nRead); q,L>PN+W
//if(nThreadID == 1) el*|@#k}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j \jMN*dmV
} %W\NYSm
%%}l[W
H=C~h\me?
Utility.log("Thread " + nThreadID + " is over!"); :rQDA=Ps
bDownOver = true; <<u]WsW{C
//nPos = fileAccessI.write (b,0,nRead); M$%ON>Kq
} &uRT/+18W3
catch(Exception e){e.printStackTrace ();} _>\33V-?b
} PiM(QR
} i@nRZ$K
?V8Fgd
XXum2eA
//打印回应的头信息 s_/@`kd{
public void logResponseHead(HttpURLConnection con) v77UE"4|c
{ 2=fM\G
for(int i=1;;i++) QOktIH
{ dxAGO(
String header=con.getHeaderFieldKey(i); jn|NrvrX
if(header!=null) nMzt_IlI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5@%Gq)z5
Utility.log(header+" : "+con.getHeaderField(header)); \ YF@r7
else 4;J.$
break; >~Zj
} X}(X\rp
} [-VH%OM
j!i*&
8xAIn>,_
public void splitterStop() oQ r.cKD ?
{ STjb2t,a
bStop = true; d.~ns4bt9
} A?#i{R
xjbI1qCfe
JseKqJ?g
} 8iaMr278W
&?bsBqpN
~/K&=xE
/* T90O.]S
**FileAccess.java *W\3cS
*//文件访问(定位，写) Zqm%qm:
package NetFox; X5/j8=G H`
import java.io.*; 'uL$j=vB
yg'CL/P
vw!7f|Pg ~
public class FileAccessI implements Serializable{ 8iY.!.G#|
GBb8}lx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jy.L/s
RandomAccessFile oSavedFile; 'XKfKv >;
long nPos; A"M;kzAfHM
z_xy*Iif
9_5>MmiB
public FileAccessI() throws IOException 6jc5B#
{ b}Gm{;s!
this("",0); L]z8'n,
} 1$E[`` n
/]z#V'
153*b^iDBh
public FileAccessI(String sName,long nPos) throws IOException 18%$Z$K,
{ VdM Ksx`r
oSavedFile = new RandomAccessFile(sName,"rw"); _@XueNU1hS
this.nPos = nPos; TDR|*Cs
oSavedFile.seek(nPos); A}9^,C$#
} v1yB
h/\Zq
OXM=@B<"
public synchronized int write(byte[] b,int nStart,int nLen) S;Sy.Lp
{ lH_pG~
int n = -1; K\Q4u4DjbJ
try{ E]~#EFc
oSavedFile.write(b,nStart,nLen); z.hq2v
n = nLen; U9`Co&Z2
} 4uO88[=
catch(IOException e) xM<aQf\j
{ ?SYmsaSr5
e.printStackTrace (); ,x&WE@tD|
} 0N!rIz
N~v<8vJq`
l^bak]9 1
return n; h~sTi
} >wqWIw.w>
+76ao7d.
-:_3N2U=+
} y{(Dv}
09vVCM;DY
j-J/yhWO&
/* <bW~!lv
**SiteInfoBean.java 3'L =S
*/ `dX0F=Ag?
package NetFox; XLiwE$:t%
Xbx=h^S
VSUWX1k4%
public class SiteInfoBean { F#9^RA)9
e`LvHU_0
A?n5;mvq#
private String sSiteURL; //Site's URL M*T!nwb
private String sFilePath; //Saved File's Path imM#zy
private String sFileName; //Saved File's Name s^PsA9EAn
private int nSplitter; //Count of Splited Downloading File %8DI)n#H
e:MbMj6`
!}x-o`a5
public SiteInfoBean() VPO~veQ
{//nSplitter的缺省值为5 s."N7F
//default value of nSplitter is 5 It2:2
this("","","",5); >f&L7@
} H0B=X l[
]!"7k_
N8x&<H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MR4k#{:w
{ '.%Omc
sSiteURL= sURL; 0RSzDgX
sFilePath = sPath; 3e-E/6zH6
sFileName = sName; }3WP:Et
this.nSplitter = nSpiltter; Jc]k\U
SCn)j:gH;
eFy {VpO+
} >*B59+1P
+,7vbs3
_I,GH{lhI
public String getSSiteURL() k`'*niz
{ ZjY?T)WE9
return sSiteURL; fWIWRsy%
} -+2A@kmEJ
!YO'u'4<aK
8qfXc ^6
public void setSSiteURL(String value) 1n6%EC|X
{ `{IL.9M!f
sSiteURL = value; ON>l%Ae4G
} hH05p!2
3H>\hZ
w4Hq|N1-Y
public String getSFilePath() kbH@h2Ww
{ l LBzY`j
return sFilePath; %ib7)8Ki0
} yP` K [/
.*+jD^Gr
=l] lwA-
public void setSFilePath(String value) <dXeP/1w`
{ nsq7dhq
sFilePath = value; uB6Mjdp6
} ;/ |tU o$
c;a<nTLn
f\RTO63|O
public String getSFileName() tK#/S+l
{ ?} E M,
return sFileName; s`v$r,N0
} #tw_`yh
;Vf{3
Azr|cKu]
public void setSFileName(String value) sC2NFb-+&
{ Q_0_6,Opb
sFileName = value; ?V~vP%1
} R7h3O0@!
f?16%Rk<
u35"oLV6}#
public int getNSplitter() m9DTz$S.
{ `]l|YQz\
return nSplitter; rmWsob
} BT$Oh4y4
GlC(uhCpV
Oi@|4mo
public void setNSplitter(int nCount) 79o=HiOF99
{ Qs#;sy W@~
nSplitter = nCount; NweGK
} 0$=U\[og
} QOPh3+.5
s%~Nx3,
*]Cyc<
/* (4C)] RHQ
**Utility.java n\BV*AH
*/ c7WOcy@M
package NetFox; xh25 *y
VP~%,=
T#I}w\XlhP
public class Utility { ]ab q$Y'
_)YB*z5
QvOl-Lfc
public Utility() q@wX=
{ e5;YY
*1:kIi7_
Qs8yJH`v
} OCCC' k
`JGW8 _
//线程睡眠 Y9st3
public static void sleep(int nSecond) bB*cd!7y
{ fgF@ x
try{ 3.ShAL
Thread.sleep(nSecond); ,KPrUM}
} m?8o\|i,
catch(Exception e) pQ4HX)<P
{ Mdp'u$^!
e.printStackTrace (); `@u9 fx.
} -?IF'5z
} G"Ey%Q2K
'9&@?P;
//日志 Q?`s4P)14o
public static void log(String sMsg) :RBeq,QaO
{ 0Xn,q]@Z
System.err.println(sMsg); t9lf=+%s
} EF9Y=(0|
B=}QgXg
3e\IRF xzb
public static void log(int sMsg) ^\yz`b(A0
{ ?Ho>
System.err.println(sMsg); OekE]`~w
} 'bg'^PN>z
} C?<-`$0
<KoOJMx(
[W3sveqj&
/* e$rPXRf
**TestMethod.java T+%P+
*/ #)S&Z><<
package NetFox; <R_)[{ 7
"%_T7A ![
<w?k<%( 4
public class TestMethod { ;W\?lGOs{
(_gt!i{h
Y\4B2:Qd9
public TestMethod() )N\BC
{ ///xx/weblogic60b2_win.exe 2)QZYgfh
try{ 5rQu^6&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KAu>U3\/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'coY`B; 8
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3RFU
fileFetch.start(); 53bVhPGv
} 2zX9c<S=5
catch(Exception e){e.printStackTrace ();} =&FaMR2
jL'R4z
lWP]}Uy=5~
} l%2 gM7WMY
n5tsaU;
(W[]}k;
public static void main(String[] args) z;N`jqo
{ rc"8N<D
new TestMethod(); Qj|tD+<
} z('t#J!b
} HoeW6UV
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