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)); XI%RneuDr:
} +X* F<6mZ
for(int i=0;i<nEndPos.length-1;i++) ' D)1ka.
{ K)Df}fVOc
nEndPos = nStartPos[i+1]; CU#L *kz
} eHVdZ'%x
nEndPos[nEndPos.length-1] = nFileLength; r!=]Q}`F
} ;1{iF2jZ:
} dl*_ m3T
u|_LR5S!j
"fX_gN?
//启动子线程 hV3,^#9o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'WKu0Yi^'
for(int i=0;i<nStartPos.length;i++) WX%h4)z*
{ mC*W2#1pF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S F&M (=w<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p<of<YU)
nStartPos,nEndPos,i); ]Wy^VcqX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [ -9)T
fileSplitterFetch.start(); V9+xL 1U#
} =Q/w%8G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W;3 R;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1?D8|<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "jl1.Ah
nEndPos = " + nFileLength); {&\J)oZ
// fileSplitterFetch[nPos.length-1].start(); @K,2mhE~h
pTa'.m
\b_-mnN"
//等待子线程结束 im_w+h%^
//int count = 0; '+)6#/*
//是否结束while循环 +?URVp
boolean breakWhile = false; 9l]UE0yTL/
v?Z'[l
i>ESEmb-
while(!bStop) ]yyU)V0Iu
{ c0!Te'?
write_nPos(); ?Ia4H
Utility.sleep(500); Ux_EpC
breakWhile = true; gZw\*9Q9
4 "pS
C$]5l;`
for(int i=0;i<nStartPos.length;i++) U-Af7qO
{ #t"9TP
if(!fileSplitterFetch.bDownOver) vqrBRlZ
{ M*g2VyZ
breakWhile = false; $x;tSJ)m~
break; i:l80 GK
} httls>:xB|
} y-E1]4?})
if(breakWhile) z7'n, [
break; ]sX7%3P
&M0o&C-1/
pd=7^"[};
//count++; N; rXl8
//if(count>4) b*lKT]D,
// siteStop(); S9OxI$6Y
} N+*(Y5TU
G[|3^O>P
!d:tIu{)
System.err.println("文件下载结束！"); U3mXm?f
} ::4"wU3t
catch(Exception e){e.printStackTrace ();} K&j'c
} z`\#$
rDpe_varA
f?2zLE>u
//获得文件长度 mcvDxjk,h
public long getFileSize() "F&Tnhh4
{ LTg?5GwD\j
int nFileLength = -1; l9]o\JFXk
try{ *Zc9yZl2
URL url = new URL(siteInfoBean.getSSiteURL()); Rb{+Ki
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /DLr(
httpConnection.setRequestProperty("User-Agent","NetFox"); 4qqF v?O[r
x2sN\tOh^
V^j3y`K
int responseCode=httpConnection.getResponseCode(); 2;&mkcK'
if(responseCode>=400) ?+3R^%`V
{ \U==f&G?J
processErrorCode(responseCode); =ft9T&ciD
return -2; //-2 represent access is error 0v;ve
} R|/Wz/$1A
#uQrJh1o8
Bfbl#ZkyL
String sHeader; jIKBgsiF/
^/G?QR
gBMta+<fE~
for(int i=1;;i++) Jm?l59bv v
{ Sq?,C&LsA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w(aUEWYL
//Utility.log(in.readLine()); 4DvdEt
sHeader=httpConnection.getHeaderFieldKey(i); ERk kSTp
if(sHeader!=null) |d5ggf.w
{ 1Pu ,:Jt
if(sHeader.equals("Content-Length")) A3xbT\xdg
{ $Xf~# uH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h!QjpzQe
break; 3)dP7rmZ
} HS7R lU^
} Xe)Pg)J1
else Xz8$Xz,O
break; L%f-L.9`u
} "pYe-_"@
} $$42pb.
catch(IOException e){e.printStackTrace ();} yj>){NcX
catch(Exception e){e.printStackTrace ();} *8/VSs
e!6eZ)l
yz2(_@R
Utility.log(nFileLength); ohtT O]\
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{K+.A 9!
return nFileLength; !TGr.R
} vnDmFqelz
Q^nG0<q+
[@g~
//保存下载信息（文件指针位置） " l.!Ed
private void write_nPos() c$/<l5Uw
{ {JTmP`&l
try{ >)4.$#H
output = new DataOutputStream(new FileOutputStream(tmpFile)); Il|GCj*N
output.writeInt(nStartPos.length); ^[0"vtb
for(int i=0;i<nStartPos.length;i++) 8*vFdoE_oO
{ STw oYn
// output.writeLong(nPos); bea|?lK
output.writeLong(fileSplitterFetch.nStartPos); t~q?lT
output.writeLong(fileSplitterFetch.nEndPos); f KHse$?_
} M'YJ"
output.close(); I`3d;l;d
} _n7%df
catch(IOException e){e.printStackTrace ();} h:_NA
catch(Exception e){e.printStackTrace ();} ~bWhth2*
} JXL'\De ;
m!;G/s*
>n(F4C-pl
//读取保存的下载信息（文件指针位置） TFYw
private void read_nPos() t]4!{~,
{ S3QaYq"v
try{ 1}`2\3,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y!F!@`%G
int nCount = input.readInt(); 'bl%Y).9w
nStartPos = new long[nCount]; hc"6u\>
nEndPos = new long[nCount]; <M=';h^w2
for(int i=0;i<nStartPos.length;i++) f P+QxOz
{ `6UtxJSx
nStartPos = input.readLong(); W5|j1He&
nEndPos = input.readLong(); C[R`Ml
} +eC3?B8rN
input.close(); .3(;9};
} _Cj(fFL
catch(IOException e){e.printStackTrace ();} %oR>Uo
catch(Exception e){e.printStackTrace ();} M= atls
} URLk9PI
x+K gc[r
3Mur*tj#
private void processErrorCode(int nErrorCode) ERp{gB2U?
{ w?*jdwh,'
System.err.println("Error Code : " + nErrorCode); %TDXF_.[
} CGkI\E
jK e.gA
_%;M9Sg3
//停止文件下载 u|T%Xy=LU
public void siteStop() Fk aXA.JE
{ UUGe"]V^g:
bStop = true; YlrB@mE0n$
for(int i=0;i<nStartPos.length;i++) ]r!QmWw~V
fileSplitterFetch.splitterStop(); /-><k,mL?
q P'[&h5Y
Rh[Ibm56
} MJA~jjy4
} z$66\/V']
//负责部分文件的抓取 =D}4X1l
**FileSplitterFetch.java RvR:e|
*/ d[S#Duz<&
package NetFox; %Sul4: D#
XO%~6Us^
THYVT%v
import java.io.*; vkuc8 li
import java.net.*; v[smQO
ex!XB$X
xb]odYGdW
public class FileSplitterFetch extends Thread { V!W1fb7V
(2d3jQN`
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String sURL; //File URL yZ5x88>
long nStartPos; //File Snippet Start Position }f]b't
long nEndPos; //File Snippet End Position M}u1qXa
int nThreadID; //Thread's ID oE6|Zw
boolean bDownOver = false; //Downing is over Fav^^vf*1
boolean bStop = false; //Stop identical -w\M-wc/$
FileAccessI fileAccessI = null; //File Access interface ljuNs@q
1TIlINlJ
Ww=O=c5uOu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e$32
{ GyuV %
this.sURL = sURL; =&N$Vqn
this.nStartPos = nStart; -<PC"B
this.nEndPos = nEnd; Vha'e3o!
nThreadID = id; 4T%cTH:.9N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3(C :X1
} (![t_r0
Ox|TMSb^
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public void run() >(OYK}ZN
{ \q,s?`+B
while(nStartPos < nEndPos && !bStop) @0D![oA
{ TW2Z=ks=
x2@,9OUx
$ o" L;j
try{ VyY.r#@
URL url = new URL(sURL); +YuzpuxjJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q-(Dk?z{
httpConnection.setRequestProperty("User-Agent","NetFox"); DFc [z"[
String sProperty = "bytes="+nStartPos+"-"; F3Dt7q
httpConnection.setRequestProperty("RANGE",sProperty); ol<lCp
Utility.log(sProperty); ~$Y|ca
GkciA{
+aj^Cs1$
InputStream input = httpConnection.getInputStream(); i5VG2S
//logResponseHead(httpConnection); 06jMj26!
GQ[pG{_+
=LK}9ViH
byte[] b = new byte[1024]; V~[:*WOX
int nRead; kZv*rWAm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9ad6uTc
{ C.( yd$,
nStartPos += fileAccessI.write(b,0,nRead); f1J%]g!
//if(nThreadID == 1) r6MB"4xd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V_f`0\[x
} =hGJAU
'#<> "|
m!:.>y
Utility.log("Thread " + nThreadID + " is over!"); drIK(u\_
bDownOver = true; l2s{~IC
//nPos = fileAccessI.write (b,0,nRead); pC^2Rzf
} 'W(xgOP1
catch(Exception e){e.printStackTrace ();} (AuPZ
} hbfsHT
} ;_N"Fdl
:3 y_mf>
<sc\EK
//打印回应的头信息 x6%#wsvS
public void logResponseHead(HttpURLConnection con) {xToz]YA
{ Ye@t_,)x
for(int i=1;;i++) p[-{]!
{ k}U JVH21k
String header=con.getHeaderFieldKey(i); h0lu!m#\_
if(header!=null) m8HYWzN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A9;0y jae
Utility.log(header+" : "+con.getHeaderField(header)); e#khl9j*bt
else Wcn[gn<
break; [ f34a
} ^K;hn,R=
} !oGQ8 e
?+\E3}:
:XYy7xz<
public void splitterStop() JGgxAd{L
{ B9^R8|V
bStop = true; qtY m!g
} \8>oJR 6
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Yf=FeH7"
} UJn/s;$.e
8gI\zgS
5(#-)rlGj
/* VMF|iB
**FileAccess.java t%$@fjz
*//文件访问(定位，写) OpQ8\[X+
package NetFox; KuXkI;63J>
import java.io.*; H`el#tt_
NnOI:X {
m|1n x
public class FileAccessI implements Serializable{ H;y}-=J+
!.-.#<<_a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %E.S[cf%8&
RandomAccessFile oSavedFile; gt@SuX!@{^
long nPos; Q1T@oxV
jI0]LD1k
tl^m=(ZQ
public FileAccessI() throws IOException O,irpQ
{ ?(D}5`Nfu
this("",0); 6pm~sD
} {i;6vRr
7"K^H]6u30
z6cYC,
public FileAccessI(String sName,long nPos) throws IOException $3#%aA!(#
{ FUqt)YHi
oSavedFile = new RandomAccessFile(sName,"rw"); Xm@aYNV
this.nPos = nPos; }N]!0Ka
oSavedFile.seek(nPos); g_M^E-3
} LM6]kll
eXG57<t ON
pBU]=[M0
public synchronized int write(byte[] b,int nStart,int nLen) +>#e=nH
{ M5O'=\+,F
int n = -1; }"4roJ
try{ zo44^=~%
oSavedFile.write(b,nStart,nLen); hVf^
n = nLen; On%,l
} )E-E0Hl>7
catch(IOException e) YxyG\J\|,
{ Ay%:@j(E
e.printStackTrace (); wv^b_DR
} (OqHfv
4swKjN &
WjOH/$(
return n; choL%g}
} nq@5j0fK
5#!ogKQ(i
o(Kcs-W2
} 9-93aC.|}
Ux_<d?p
>[Rz <yv
/* VDa|U9N
**SiteInfoBean.java T V;BNCg
*/ >a@>N
package NetFox; +?V0:Kz]
k>>`fE\K
W_m!@T"@H
public class SiteInfoBean { MS{{R+&
p8>R#9
(:OHyeNt
private String sSiteURL; //Site's URL N&x:K+Zm.
private String sFilePath; //Saved File's Path v.b5iv5
private String sFileName; //Saved File's Name 0!_*S )
private int nSplitter; //Count of Splited Downloading File )!a$#"'
^aptLJF
D'n7&Y
public SiteInfoBean() WW6yFriuW
{//nSplitter的缺省值为5 ~S;!T
//default value of nSplitter is 5 Lzz)n%y5
this("","","",5); waQtr,m)
} PkJcd->
?l9=$'
u-39r^`5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QkE,T0,/?h
{ Ut_mrb+W
sSiteURL= sURL; nsl*Dm"*F
sFilePath = sPath; 9A+M|;O
sFileName = sName; 9GPb$gtx
this.nSplitter = nSpiltter; j{"[Ec
"Z~`e]>
Pw xIz
} o&,Y<$!:VH
[TEcg^
Z(UD9wY5m
public String getSSiteURL() 4|F#gK5E
{ tN}c0'H
return sSiteURL; XN(tcdCG
} HEpM4xe$
8Z!*[c>K-?
+f|6AeE
public void setSSiteURL(String value) IfB/O.;Kz
{ m>YWxa
sSiteURL = value; <`+zvUx^?
} f?0D%pxc}&
17i$8
/x/4NeD
public String getSFilePath() N]u2ql&
{ 6Hn)pD#U
return sFilePath; m#MlH=-
} agW9Go_F[
B52H(sm
o\60n
public void setSFilePath(String value) pUhc3L
{ *:j-zrwu&
sFilePath = value; gY%&IHQ'
} 4Cd#sQ
QPV@'.2m
"Y(^F bs
public String getSFileName() 48k7/w\
{ Uz $ @(C
return sFileName; RJ*F>2
} f@x_#ov
\n;g2/VjO
mmcdtVe
public void setSFileName(String value) _k|g@"
{ 0 {,h.:
sFileName = value; V&R$8tpz
} GmAj</~
K plM['uF
JaFUcpZk$
public int getNSplitter() %wtXo BJ
{ zHqhl}
return nSplitter; rg*^w!
} FW5}oD(H
yp?w3|`4;
hv{87`L'K(
public void setNSplitter(int nCount) pX^=be_
{ b"&E,=L
nSplitter = nCount; y<v|X2
} T g{UK
} cyHU\!Z*Zq
X\mz+al>[
{=6)SBjf
/* x,f>X;04
**Utility.java Mlwdha0
*/ !3?yG
package NetFox; +0dT^Jkqg
.OV-`TNWj
X?R |x[
public class Utility { D>Ua#<52q
|mvM@V;^8{
o"\{OX
public Utility() p>&S7M/9
{ -tMA
b@!:=_Mr
fzyzuS$
} EU9[F b]
)6 k1 P
//线程睡眠 3u4:l
public static void sleep(int nSecond) V pH|R
{ *k4+ioFnKE
try{ L W?&a3e
Thread.sleep(nSecond); A9iQ{l
} )gjGG8Ee
catch(Exception e) 4gya]
{ pkW5D
e.printStackTrace (); VW~Xbyf
} j)BQMtt&U
} _<3r'Y,
fRFYJFc n
//日志 "5h_8k~sQ
public static void log(String sMsg) @ce3%`c_
{ 9':/Sab:7v
System.err.println(sMsg); oAaf)?8
} ^9s"FdB]24
P|8e%P
/0l-mfRr
public static void log(int sMsg) ^H-QYuz:T0
{ }|,EU!nDi
System.err.println(sMsg); 6$DG.p
} xh`Du|jvm
} _\!0t
'(XW$D
Q<C@KBiVE
/* 9GaL0OWo
**TestMethod.java n{3|E3
*/ `[&v
package NetFox; (<n>EF#
=<TO"
@| P3
public class TestMethod { P.!;Uf}32
[{?;c+[
*n,UOHlO
public TestMethod() m qpd
{ ///xx/weblogic60b2_win.exe uZ-`fcCjD
try{ dhs#D:/{9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8>m1UONr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )#Y|ngZ_>
SiteFileFetch fileFetch = new SiteFileFetch(bean); +*<K"H|,
fileFetch.start(); tfsh!)u?
} &`m~o/
catch(Exception e){e.printStackTrace ();} %Dl_}
Ty.drM
}\U0[x#q
} 5qeT4| Ol
Na-q%ru
Up'."w_zE
public static void main(String[] args) XQ4dohGCP
{ ynxWQ%d(`
new TestMethod(); ?$2q P`-
} 9W$mDw6f
} E $<;@
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