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)); )vsiX}3
} @.-g
for(int i=0;i<nEndPos.length-1;i++) ,:-S<]fS{_
{ ;tI=xNre`1
nEndPos = nStartPos[i+1]; FpfOxF6A3
} !xMyk>%2
nEndPos[nEndPos.length-1] = nFileLength; Nm<3bd
} Rcf_31 L
} W k'()N
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T"t3e=xA
//启动子线程 +J$[RxQ#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '@HWp8+
for(int i=0;i<nStartPos.length;i++) s_K:h
{ [e ;K$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SMgf(N3]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XN]kNJX
nStartPos,nEndPos,i); :SSe0ZZ_6b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J']1^"_'
fileSplitterFetch.start(); &oYX093di
} p0uQ>[NV0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0<Px2/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @g""*T1:$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Gy 'l;2
nEndPos = " + nFileLength); 1c,$D5#
// fileSplitterFetch[nPos.length-1].start(); ,g{`M]Ov
8:-[wl/@
J}KATpHs
//等待子线程结束 @y9_\mX!s
//int count = 0; E<'3?(D9hL
//是否结束while循环 /l0\SVwa>
boolean breakWhile = false; a)4.[+wnRf
bWwc2##7jo
i+jSXn"_
while(!bStop) F[115/
{ ;hmy7M1%
write_nPos(); ?bQ~+M\
Utility.sleep(500); Az6f I*yP
breakWhile = true; =4/lJm``
I9ubVcV8
>!wX%QHH
for(int i=0;i<nStartPos.length;i++) &K)c*'l
{ {Rjj
if(!fileSplitterFetch.bDownOver) [1dlV/
{ RMmDcvM"k
breakWhile = false; # o)a`,f
break; N4}/n
} Z|uUE
} >I8R[@
if(breakWhile) 5>"$95D
break; a~7`;Ar
S!2M?}LU
[$]vi`c2
//count++; nod?v2%
//if(count>4) -O\!IXG^
// siteStop(); _*9eAeJ
} XJC|6"n
%IW=[D6Tg
&voyEvX/S
System.err.println("文件下载结束！"); wvcG <sj
} 3uz@JY"mK
catch(Exception e){e.printStackTrace ();} !V$m!i;
} 3rTYe6q$U
-2w\8]u
4At%{E
//获得文件长度 Obrv5%'
public long getFileSize() V3xC"maA@
{ gx#xB8n
int nFileLength = -1; c@~\ FUr
try{ 7z)Hq./3@
URL url = new URL(siteInfoBean.getSSiteURL()); BE:HO^-.1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w8kp6_i'
httpConnection.setRequestProperty("User-Agent","NetFox"); 7\rz*
=\ iV=1iB
6^s=25>p
int responseCode=httpConnection.getResponseCode(); "D2`=D!+
if(responseCode>=400) ,*Tf9=z
{ .4Jea#M&x
processErrorCode(responseCode); G 2+A`\]
return -2; //-2 represent access is error zdzTJiY2[Z
} ZTVX5"#Q
4W*52*'F,
S j)&!
String sHeader; 0j7W\'!t
BYyR-m
p./zW )7+
for(int i=1;;i++) A|I7R-
{ T' %TMA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |#LU"D
//Utility.log(in.readLine()); GP<A v1
sHeader=httpConnection.getHeaderFieldKey(i); 9sFZs]uM
if(sHeader!=null) G}&B{Ir
{ e]'ui<`
if(sHeader.equals("Content-Length")) 6x^#|;e>lI
{ (2[tQ`~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1CU-^j
break; r;g[<6`!S
} "6w-jT
} Vi?[yu<F
else 93$'PwWgiF
break; 1\=)b< y
} C,P>7
} BRPvBs?Q,{
catch(IOException e){e.printStackTrace ();} s%2w&Us*
catch(Exception e){e.printStackTrace ();} IKMkpX!]
R7r` (c!
HJo&snT3
Utility.log(nFileLength); :$~)i?ge<5
Jajo!X*Wai
"9jt2@<
return nFileLength; aJ}y|+Cj
} k(pI5N}pJZ
X+z!?W*a
3vfm$sx@
//保存下载信息（文件指针位置） uPr'by
private void write_nPos() 2w>WS#
{ PTWP7A[
try{ [fiB!G]?
output = new DataOutputStream(new FileOutputStream(tmpFile)); !1$QNxgi
output.writeInt(nStartPos.length); /bv1R5
for(int i=0;i<nStartPos.length;i++) Q0K2md_%x
{ N_rz~$|@9
// output.writeLong(nPos); ?n)d: )Ud"
output.writeLong(fileSplitterFetch.nStartPos); RZ-=UIf
output.writeLong(fileSplitterFetch.nEndPos); w=Ac/12
} <u]M):b3
output.close(); ?`bi8 Ck
} N DZ :`D
catch(IOException e){e.printStackTrace ();} 1@rI4U@D
catch(Exception e){e.printStackTrace ();} v;AsV`g
} }:<`L\8q\
4$#nciAe
tgSl(.
//读取保存的下载信息（文件指针位置） Anr''J&9`H
private void read_nPos() 1O]'iS"
{ epuN~T
try{ >?aPXC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {AUhF}O
int nCount = input.readInt(); mSF>~D1_
nStartPos = new long[nCount]; VW:WB.K$
nEndPos = new long[nCount]; &TJMopVn
for(int i=0;i<nStartPos.length;i++) 4r&DW'
{ e&sZ]{uD
nStartPos = input.readLong(); meey5}
nEndPos = input.readLong(); >-J%=P
} _;L%? -2c
input.close(); }Q&zYC]d
} z*n
catch(IOException e){e.printStackTrace ();} Yef=HSzo
catch(Exception e){e.printStackTrace ();} (8T36pt~
} `Sgj!/!F
"Zm**h.t
& mwQj<Z
private void processErrorCode(int nErrorCode) d5Hp&tm
{ +a1Or
System.err.println("Error Code : " + nErrorCode); H3\4&q
} nwuH:6~"
eB%hP9=:x
XrP'FLY o
//停止文件下载 B_R J;.oH
public void siteStop() p}H:t24Cr5
{ vP6NIcWC3
bStop = true; t|-TG\Q X
for(int i=0;i<nStartPos.length;i++) t6u>_She
fileSplitterFetch.splitterStop(); ;e Iqxe>
`o/G0~T)
&O8vI,M
} riw0w
} 7q\&
//负责部分文件的抓取 RP[^1
**FileSplitterFetch.java 2E5n07,
*/ +g %h,@
package NetFox; $d0xJxM
WXHvUiFf
LX f r
import java.io.*; U}f"a!
import java.net.*; DBTeV-G9~R
OM,Dy&Y
h0**[LDH
public class FileSplitterFetch extends Thread { *rKj%Me
<"/b 5kc
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String sURL; //File URL 7`eg;s^
long nStartPos; //File Snippet Start Position (h{"/sR
long nEndPos; //File Snippet End Position CCoT
int nThreadID; //Thread's ID HGycF|]2
boolean bDownOver = false; //Downing is over ?{=&Ro
boolean bStop = false; //Stop identical rtM29~c>@
FileAccessI fileAccessI = null; //File Access interface )M3}6^s]
xXb7/.*qE
Ln-UN$2~F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M2Q*#U>6r
{ L#huTKX}
this.sURL = sURL; JG^fu*K
this.nStartPos = nStart; wFbw3>'a9
this.nEndPos = nEnd; LV}Z[\?
nThreadID = id; ohEIr2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F:$*0!
} Dh+<|6mx
z`]sWi F0
QC\r|RXW
public void run() #su R[K*S
{ Z$*m=]2
while(nStartPos < nEndPos && !bStop) ,8.Fd|#L
{ .)(5F45Wg
(1%O;D.*?{
N>V\
try{ ,zF^^,lO7
URL url = new URL(sURL); Cx~,wk;=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A4K8DP
httpConnection.setRequestProperty("User-Agent","NetFox"); y26?>.!
String sProperty = "bytes="+nStartPos+"-"; gn-@OmIs
httpConnection.setRequestProperty("RANGE",sProperty); hl}iw_e
Utility.log(sProperty); cQzUR^oq,
cnw?3/J
H8!; XB
InputStream input = httpConnection.getInputStream(); 8kdJ;%^N
//logResponseHead(httpConnection); 2^aXXPC
2xxw8_~C
i<\WRzVT
byte[] b = new byte[1024]; #'y4UN
int nRead; DpbprT7_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _ASyGmO{
{ .n\j<Kq
nStartPos += fileAccessI.write(b,0,nRead); 6uS;H]nd<
//if(nThreadID == 1) ,vDSY N6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Fj*sS8
} 8*x/NaH /\
\Gl>$5np
`8 Ann~Z|k
Utility.log("Thread " + nThreadID + " is over!"); PAD&sTjE*
bDownOver = true; D4OJin^}
//nPos = fileAccessI.write (b,0,nRead); 2 xE+"?0
} 'Lu d=u{
catch(Exception e){e.printStackTrace ();} f|+aa6hN
} E!EENg
} 1[] 9EJ
QnJd}(yN
Mg~62u
//打印回应的头信息 V}aZ}m{J
public void logResponseHead(HttpURLConnection con) *-eDUT|O
{ `RlMfd
for(int i=1;;i++) @f!r"P]
{ ]mR!-Fqj
String header=con.getHeaderFieldKey(i); mI>=S
if(header!=null) t) uS7y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /1BqC3]tL
Utility.log(header+" : "+con.getHeaderField(header)); jR[b7s
else %n{ue9
break; jvQpfd
} Vi=u}(*
} B<{Yj}..
e;8nujdG"
(jI_Dk;
public void splitterStop() {Gvv^.H7
{ IkP; i_|
bStop = true; GMKY1{
} dbG902dR
G2 0
]?*'[
} wh2Ljskda8
wiP )"g.t
"'3QKeM1
/* ' e:rL.
**FileAccess.java $!goM~pZ
*//文件访问(定位，写) ,a34=,
package NetFox; "1wjh=@z
import java.io.*; .b|!FWHNS
q[TGEgG
s 9n_s=w
public class FileAccessI implements Serializable{ Pi5($cn
m;cgX#k5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *@eZt*_
RandomAccessFile oSavedFile; bH}?DMq]O
long nPos; w6
\R[f< K%
,1 ^IFBJ
public FileAccessI() throws IOException K3^2;j1F Q
{ LEd@""h
this("",0); _ SJFuv/
} G-[.BWQ
:>-&
7-Mm+4O9
public FileAccessI(String sName,long nPos) throws IOException }B`T%(11=
{ !B/5@P
oSavedFile = new RandomAccessFile(sName,"rw"); MLvd6tIv,
this.nPos = nPos; AhU
oSavedFile.seek(nPos); CHckmCgf4
} R4%}IT^%P
3H`r|R
gxc8O).5vY
public synchronized int write(byte[] b,int nStart,int nLen) "ph[)/u;
{ )v+\1
int n = -1; ~o27~R ]
try{ VXO.S)v2J
oSavedFile.write(b,nStart,nLen); ]sDlZJX<M
n = nLen; }u.I%{4
} y_M,p?]^,
catch(IOException e) P?|>, \t
{ ,uL}O]L
e.printStackTrace (); c7@[RG !
} Y'O3RA5E
B8 r#o=q1
WelB"L
return n; bL2b^UB~%
} -Mzm~@_s]
,In}be$:
[j 'lB
} (5GjtFojY|
"+A8w
om{aws;
/* *6wt+twH
**SiteInfoBean.java 5Ve T8/7Q
*/ \# _w=gs<i
package NetFox; AvcN,
IoCi(N;
|$D`*
public class SiteInfoBean { 7g.3)1
e=Q{CsP
YSru5Q
private String sSiteURL; //Site's URL B*otquz
private String sFilePath; //Saved File's Path _ykT(`.#
private String sFileName; //Saved File's Name do DpTwvh
private int nSplitter; //Count of Splited Downloading File fl+2'~
Yu:!l>
s:*" b'
public SiteInfoBean() !"SuE)WM
{//nSplitter的缺省值为5 Lnc>O'<5P9
//default value of nSplitter is 5 [!YSW'
this("","","",5); SquuK1P=
} -d*je{c|
<xh";seL
78kT}kgW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >dfk2.6e
{ #;hYJ Y
sSiteURL= sURL; \@$V^;OP/
sFilePath = sPath; &5n0J
sFileName = sName; _)MbvF
this.nSplitter = nSpiltter; vt(cC))
EttQ<z_T
;mwU>l,4
} k? !'OHmBL
s!?T$@a=
lr9s`>9
public String getSSiteURL() #T08H,W/
{ w0,rFWS
return sSiteURL; O"emse}Z
} 'a=' (,%
C%Fc%}[
PDhoCAh !
public void setSSiteURL(String value) I*0TI@Lo
{ *eAzk2
sSiteURL = value; .$-GGvN]
} B8NMo5a
:y^%I xs{1
?dY|,_O
public String getSFilePath() -GT&46hX
{ sW0<f&3
return sFilePath; '\R/-.
} i|CAN,'
o,_R;'\E[a
wqA7_ -
public void setSFilePath(String value) tB<|7
{ .iZo/_
sFilePath = value; `Zd\d:Wyv
} 2py [P
}\]J?I+A
KVp3pUO
public String getSFileName() Iz9b5
{ E&>=
return sFileName; W*9*^
} >=d%t6%(
AZfW
M{O8iq[
public void setSFileName(String value) m!Fx#
{ s]2_d|Y
sFileName = value; m[D]4h9
} {qb2!}FQ
Kq;s${ |G
lR0WDJv
public int getNSplitter() O_^t u?x
{ f~w!Z
return nSplitter; 8'o6:
} b9TsuY
4{rj 4P?
D}]u9jS1
public void setNSplitter(int nCount) iDV.C@
{ tVhf1TH#
nSplitter = nCount; $kd9^lj#[
} Q3 yW#eD
} #L9F\ <K
,g:\8*Y>'
8"C[sRhz
/* p #Y2v
**Utility.java fm$)?E_Rp
*/ -gVsOX0
package NetFox; &z?:s
rixt_}aE
@h!nVf%fe
public class Utility { /7hC /!@
5?XIp6%x
o>Q=V0?
public Utility() OtZc;c
{ i?B(I4a!G
r"&VG2c0K
[xHHm5$
} XY!0yAK(!
%IK[d#HO
//线程睡眠 'yNS(Bg=
public static void sleep(int nSecond) :Hq#co
{ Ih^ziDcW
try{ Q<T+t0G\O-
Thread.sleep(nSecond); Uq^-km#a
} L'r gCOJ<
catch(Exception e) UB,:won
{ >Qx :l#B
e.printStackTrace (); !30BR|K*
} T[ltOQw?Y
} PAS0 D #
u_jhmKr~
//日志 .A apO}{
public static void log(String sMsg) [(m+Ejzi%
{ ][1 iKT
System.err.println(sMsg); #b94S?dq
} n 'E:uXv"
+MyXIWmD
>$G'=N:=X&
public static void log(int sMsg) x`JhNAO>
{ !dGSZ|YZ
System.err.println(sMsg); ?<STl-]&
} SYwB #|
} GL'l "L
Z~v-@
jW;g{5X
/* <3!Q Xc
**TestMethod.java tO+Lf2Ni+
*/ ].HHTCD`c
package NetFox; D8f4X w}=
si#1sdR
raJv$P
public class TestMethod { SSysOeD+
U o[\1)
'w?}~D.y
public TestMethod() 5F$~ZDu
{ ///xx/weblogic60b2_win.exe HUalD3 \
try{ 'g:.&4x_w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0bl8J5Ar5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D.*o^{w|
SiteFileFetch fileFetch = new SiteFileFetch(bean); k nljc^
fileFetch.start(); u{5+hZ
} xl ,(=L]
catch(Exception e){e.printStackTrace ();} %gEgpJd
";;Nc>-Y
v@QfxV2
} @G^m+-
Hv-f :P O
Dbw{E:pq
public static void main(String[] args) +d=w%r)
{ sw+vyBV)r
new TestMethod(); 1.I58(0~+
} z -uW,
} %<{1N|
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