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)); 9"N~yKa`"K
} +G$4pt|=
for(int i=0;i<nEndPos.length-1;i++) >f|||H}Snw
{ P9/q|>F
nEndPos = nStartPos[i+1]; "SNn^p59k
} |'e^QpU5
nEndPos[nEndPos.length-1] = nFileLength; ^-TE([bW
} l#g\X'bK
} WO7z
8^kGS-+^
/}((l%UE.
//启动子线程 IY_iB*T3jt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]P9l jwR
for(int i=0;i<nStartPos.length;i++) B |5]Jm]
{ 4(#'_jS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1NbG>E#Ol
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MS nG3]{z
nStartPos,nEndPos,i); %2}-2}[>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ADz ^\
fileSplitterFetch.start(); D.r<QO~6B
} 2+RUTOv/d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VRVO-Sk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .Hescg/S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rm2yPuOU}A
nEndPos = " + nFileLength); ~G)S
// fileSplitterFetch[nPos.length-1].start(); [xK3F+
B+$%*%b
!`M,XSp(
//等待子线程结束 >Ifr [
//int count = 0; I:E`PZ
//是否结束while循环 "x#-sZ=
boolean breakWhile = false; nB_?ckj,
'<gI8W</
raW>xOivR
while(!bStop) g!|=%(G=
{ k 9_`(nx
write_nPos(); ^dI424
Utility.sleep(500); kPKB|kP\
breakWhile = true; ,j#XOy`mzy
V"[g.%%Y
,A9]CQ
for(int i=0;i<nStartPos.length;i++) hE &xE;
{ >d(~#Z`
if(!fileSplitterFetch.bDownOver) EW}Bzh>b
{ ##q2mm:a9P
breakWhile = false; zU,9T
break; 3Lfqdqj
} 0^v`T%|fTX
} KsddA
if(breakWhile) Lt2u,9
break; kT|dUw9G
_1!7V3|^
xn?a. 3b'
//count++; bc*X/).
//if(count>4) <NHH^M\N
// siteStop(); R$EW4]j
} XP`Nf)3{Yd
9,c(ysv"
j9m_jv
System.err.println("文件下载结束！"); ~Q*%DRd&Z-
} 7( #:GD
catch(Exception e){e.printStackTrace ();} T*I{WW
} #./fY;:cj
-Sqz5lo
|a8iZ9/D6
//获得文件长度 B=U 3
public long getFileSize() +[Dx?XM
{ u:}%xD6
int nFileLength = -1; Y`KqEjsC*
try{ QfmJn((
URL url = new URL(siteInfoBean.getSSiteURL()); ZVW'>M7.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @MoKWfc
httpConnection.setRequestProperty("User-Agent","NetFox"); "H2EL}3/]
WEAT01
mR!1DQ.\<
int responseCode=httpConnection.getResponseCode(); e*sfPHt
if(responseCode>=400) HsxVZ.dS
{ =WyDp97@+
processErrorCode(responseCode); %Wg'i!?cB
return -2; //-2 represent access is error C:GK,?!Jn'
} u+dLaVlLJ
} FE>|1
wDw[RW3
String sHeader; N[?N5~jG
pD(j'[
Fzm*Pz3
for(int i=1;;i++) ;:iY)}
{ 8bxfj<O,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O8^A5,2@3>
//Utility.log(in.readLine()); PoNi"Pv
sHeader=httpConnection.getHeaderFieldKey(i); 9q)Kfz
if(sHeader!=null) 6o^,@~:R
{ `34zkPB??
if(sHeader.equals("Content-Length")) 5sdn[Tt##
{ "<6G6?sz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P)"noG_'i
break; C^s^D:
} a,Sw4yJ!Q
} |U~<3.:m:
else lVd^ ^T*fh
break; *FWMn.
} [m+2(I1
} '-QwssE
catch(IOException e){e.printStackTrace ();} 02Y]`CXj
catch(Exception e){e.printStackTrace ();} M\vwI"
Cmu@4j&
MvuQz7M#d
Utility.log(nFileLength); % BVs47g
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z__EYh
return nFileLength; 4Xgg%@C
} FSP+?((
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0;hqIJcE:\
//保存下载信息（文件指针位置） +00b)TF
private void write_nPos() UMv.{iEj
{ wrviR
try{ DP[IZC
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,aOl_o -&
output.writeInt(nStartPos.length); _> f`!PlB|
for(int i=0;i<nStartPos.length;i++) a Ve'ry
{ >~#yu&*D
// output.writeLong(nPos); B`YTl~4
output.writeLong(fileSplitterFetch.nStartPos); 9Q.rMs>qj
output.writeLong(fileSplitterFetch.nEndPos); S O4u9V
} \@Ts+7%
output.close(); b`(}.r?W
} vNVox0V
catch(IOException e){e.printStackTrace ();} ?fiIwF)
catch(Exception e){e.printStackTrace ();} Amp#GR1CA
} y?rPlA_
\j+1V1t9
0\H\lKcK
//读取保存的下载信息（文件指针位置） |<HPn4 ,X
private void read_nPos() :Hn6b$Vy8
{ :uP,f<=)K
try{ kh!FR u h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [O$Wa:< 0x
int nCount = input.readInt(); VdPtPq1
nStartPos = new long[nCount]; ?OId\'q
nEndPos = new long[nCount]; \?w2a$?6w
for(int i=0;i<nStartPos.length;i++) !6n_}I-W
{ rTM}})81
nStartPos = input.readLong(); hmvfw:Nq4
nEndPos = input.readLong(); Nc1"g1JR
} &@G:G(
input.close(); +"x,x
} wHzEMwY_
catch(IOException e){e.printStackTrace ();} !-ok"k0,u
catch(Exception e){e.printStackTrace ();} f6EZ( v
} \"qY"V
Vl5`U'^qx
) dn(G@5
private void processErrorCode(int nErrorCode) T m,b,hi$
{ oin$-i|Xp!
System.err.println("Error Code : " + nErrorCode); hM@ HA
} G(Lzf(
T{Gj+7bQ~
!_"@^?,q
//停止文件下载 ]}*R|1
public void siteStop() BYpG
{ _?<|{O
bStop = true; 7OC#8,
for(int i=0;i<nStartPos.length;i++) jDKO} bQ
fileSplitterFetch.splitterStop(); W_||6LbZy
a!ud{Dx
4Z1ST;
} vY4\59]P
} %WSo b@f8
//负责部分文件的抓取 s&A} h
**FileSplitterFetch.java BD68$y
*/ @"hb) 8ng
package NetFox; (gEBOol
N<|@ymi
b+,';bW
import java.io.*; Mxe}B'
import java.net.*; N+++4;
! _f9NK
gaQdG=G8$
public class FileSplitterFetch extends Thread { 48c1gUwoP
s2teym,uG
0x'#_G65y
String sURL; //File URL :S.9eFfa
long nStartPos; //File Snippet Start Position (XeE2l2M
long nEndPos; //File Snippet End Position %Da8{%{`Pc
int nThreadID; //Thread's ID Mx&&0#;r
boolean bDownOver = false; //Downing is over 6tB+JF
boolean bStop = false; //Stop identical E;,u2[3
FileAccessI fileAccessI = null; //File Access interface Ci?Ss+|
t|a2;aq_
GU4'&#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4P'*umJi
{ q_TRq:&.
this.sURL = sURL; MTsM]o
this.nStartPos = nStart; OSlvwH%(EE
this.nEndPos = nEnd; M}d_I+
nThreadID = id; %Qc La//
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Hcl(3>Jn2
} >v:y?A,
5Ec6),+&
%oq{L]C(rf
public void run() |*:'TKzNS
{ TX$r`~
while(nStartPos < nEndPos && !bStop) JM=JH 51`
{ GYJ80k|
MJOz.=CbhR
;hYS6
try{ cU;iUf
URL url = new URL(sURL); }M1`di4e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '3_]Gu-D
httpConnection.setRequestProperty("User-Agent","NetFox"); Ge2q%
String sProperty = "bytes="+nStartPos+"-"; *-MM<|Qt
httpConnection.setRequestProperty("RANGE",sProperty); O/,aJCe
Utility.log(sProperty); Ai:BEPKe
{/"2Vk<H8
@HQ`~C#Z'
InputStream input = httpConnection.getInputStream(); )#P; x"
//logResponseHead(httpConnection); 1>*#%R?W
L0*nm.1X
u\ #"L
byte[] b = new byte[1024]; wLmhy,
int nRead; "7!;KHc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Y.vJz
{ 1xD=ffM>8N
nStartPos += fileAccessI.write(b,0,nRead); WfWN(:dF
//if(nThreadID == 1) b6}H$Sx~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t?q@H8
} `!XY]PI+e
iJ~Zkd
uZc`jNc\
Utility.log("Thread " + nThreadID + " is over!"); .l>77zM6
bDownOver = true; {)"iiJ
//nPos = fileAccessI.write (b,0,nRead); '>&^zgr
} H18Tn!RDS
catch(Exception e){e.printStackTrace ();} d p2F
} #1`-*.u
} C 'v+f=
TatpXN\
_&N2'hG=sn
//打印回应的头信息 [K9'<Qnu
public void logResponseHead(HttpURLConnection con) KAC6Snu1
{ IOb*GTb
for(int i=1;;i++) :E_g"_
{ z*kutZ:6Y
String header=con.getHeaderFieldKey(i); MNC*Glj=
if(header!=null) x97 j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0uWR<,]
Utility.log(header+" : "+con.getHeaderField(header)); 3{""58
else b?TO=~k,
break; _z'u pb&
} i 7_ _
} /e7O$L)
^.#jF#u~
Qj,]N@7
public void splitterStop() 7[I}*3Q'
{ 4kG,*3&2
bStop = true; S/^"@?z,vE
} y=`2\L" O
N$h{Yvbn
&0NFb^8+
} 'XZ)!1N
O$IEn/%+
F{EnOr`,m=
/* \]=7!RQ\
**FileAccess.java kB/D!1 "
*//文件访问(定位，写) ,=tD8@a<
package NetFox; |p><'Q%*
import java.io.*; dik:4;
@n(Z$)8tR
D[^m{ 9_
public class FileAccessI implements Serializable{ K@#(*."
)Z(TCJ~~!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (@t(?Js
RandomAccessFile oSavedFile; o>/YAX:.!T
long nPos; 'f[T&o&L/
&$]vh
C!Rs^/
public FileAccessI() throws IOException {P{bOe
{ V>R8GSx
this("",0); --HF8_8;'
} c.,2GwW
NXNY"r7~
_h X]%
public FileAccessI(String sName,long nPos) throws IOException ;cPy1
{ >)spqu]
oSavedFile = new RandomAccessFile(sName,"rw"); AI,(z;{P
this.nPos = nPos; Sg6"WV{<
oSavedFile.seek(nPos); V#cqRE3XNi
} x/;buW-
DTaN"{
89\n;5'f4
public synchronized int write(byte[] b,int nStart,int nLen) Ytz)d/3T
{ bty/
int n = -1; #bl6sa{E
try{ #;%JT
oSavedFile.write(b,nStart,nLen); kMtwiB|7j
n = nLen; x9;gT&@H
} EGZb7:Y?
catch(IOException e) dgA-MQ5{
{ JcbwDlUb
e.printStackTrace (); -TM0]{
} Eo#u#IY
Q(<)KZIK
%kB8'a3
return n; 0JlZs]
} r:F
/C>wd
t?9v^vFR
} Q\cjPc0y
~.UrL(l=
4eikLRD,
/* 0%m)@ukb
**SiteInfoBean.java $% 1vW=d
*/ <Wp QbQM
package NetFox; ow_djv:,
Bx/L<J@
{@tv>!WW
public class SiteInfoBean { 4?-.ZUT-1
iMs5zf<M
N5i+3&
private String sSiteURL; //Site's URL hO';{Nl/$
private String sFilePath; //Saved File's Path 9(6I<]#
private String sFileName; //Saved File's Name \T<$9aNb
private int nSplitter; //Count of Splited Downloading File 2I&o69x?
>y[oP!-|P
^}:#
public SiteInfoBean() 3'^k$;^
{//nSplitter的缺省值为5 6xZ=^;H
//default value of nSplitter is 5 tQH+)*
this("","","",5); %*&UJpbA
} P#fM:z@[
,4ei2`wV
sO.`x*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L2, 1Kt7
{ z.Y$7bf)
sSiteURL= sURL; `;)\u
sFilePath = sPath; E;1Jh(58)b
sFileName = sName; tkXEHsRT
this.nSplitter = nSpiltter; ;$a@J&
mZx&Xez_G
cZT({uYGL
} RTv qls
lWqrU1Sjl
# g_Bx
public String getSSiteURL() RB+N IoQQ|
{ hWKJ,r%9;
return sSiteURL; nv0]05.4
} t`+'r}=d
h}]fnA
~M\I;8ne
public void setSSiteURL(String value) J,zO2572u
{ 4"xPr[=iG
sSiteURL = value; Rr!Y3)f;
} 7^Ns&Q
v{9t]s>B
V^\8BVw
public String getSFilePath() [-)r5Dsdq
{ i} N8(B(
return sFilePath; HO[wTB|D]
} ' 4ER00
om]4BRe
<0S,Q+&
public void setSFilePath(String value) SF5@Vg
{ 1!.(4gV
sFilePath = value; hs?sGr
} +e-G,%>9
JqMDqPIQ
ZKXo-~=>
public String getSFileName() !>>f(t4
{ .VkbYK
return sFileName; Dgx8\~(E'
} 'w14sr%
1*dRK6
kWNV%RlSx
public void setSFileName(String value) 3q`)*
{ SL,p36N
sFileName = value; 2e|N@j &
} BSkDpr1C
1ylk4@`
M4d47<'*~
public int getNSplitter() {U84 _Pi
{ &R$CZU
return nSplitter; @fa@s-wb
} 4T?h
sYdRh?Hq
3LfC{ER
public void setNSplitter(int nCount) in(U:04
{ zLF?P3^
nSplitter = nCount; KL ?@@7
} :Dd$i_3=
} +n7?S~R$
l27\diKPJ
~u.T-0F
/* .S%0
**Utility.java JkGnKm9G
*/ ;A'":vXmc
package NetFox; rYp3(k3
}=v)Js
f}L*uw
public class Utility { Uz7^1.-g4
7^M9qTEHp
m~>Y{F2
public Utility() #BQ.R,
{ 3( ]M{4j
7c;9$j
jr)7kP@
} Ed:eGm }
0x9x@gF
//线程睡眠 iA,kX\nK
public static void sleep(int nSecond) >OP+^^oZ<
{ f"(X(1F
try{ c5Q<$86
Thread.sleep(nSecond); ^{\<N()R
} (708H_
catch(Exception e) c)Ic#<e(
{ DaH?@Q
e.printStackTrace (); NWd<+-pC6
} 4Td{;Y="yF
} :aG#~-Q
3&x-}y~sg
//日志 af|5n><~A
public static void log(String sMsg) ]7Fs$y.
{ NO] 3*
System.err.println(sMsg); siTX_`0
} St<mDTi
.@"q$\
g!i45-n3gt
public static void log(int sMsg) *FfMI
{ up2+s#
System.err.println(sMsg); unJ R=~E
} U#n#7G6fRp
} KK,Z"){
zFQ&5@43
[Px'\nVf
/* {T'GQz+R"
**TestMethod.java KI]wm
*/ 4 V1bLm
package NetFox; ,+;:3gRk9
@R m-CWa
D{v8q)5r
public class TestMethod { `p'Q7m2y/b
!WkIi^T
3@n>*7/E
public TestMethod() +m}Pmi$
{ ///xx/weblogic60b2_win.exe __@zTSVb
try{ < pTTo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =H8 xSJLh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4gSH(*}
SiteFileFetch fileFetch = new SiteFileFetch(bean); b.O9ITR
fileFetch.start(); J4=_w
} CU:o*;jP
catch(Exception e){e.printStackTrace ();} dx,=Rd5'
&ff&Y.q~
WhBpv(q}.
} 8SmnMt
hSGb-$~F
7B3w\
public static void main(String[] args) *[eL~oN.c
{ ySbqnw'
new TestMethod(); 39 Y(!q
} @>x pYV
} mfny4R1_
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