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)); N)0V6q"
} PgMU|O7To
for(int i=0;i<nEndPos.length-1;i++) sCrOdJ6|
{ s%OPoRE
nEndPos = nStartPos[i+1]; D.;iz>_}Y
} VX{9g#y$j
nEndPos[nEndPos.length-1] = nFileLength; 1RM@~I$0
} z7$,m#tw
} PYhRP00}M
2M`:/shq
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//启动子线程 -+)06BqF}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9Z!|oDP-
for(int i=0;i<nStartPos.length;i++) 8}_M1w6v
{ 58>C,+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [19QpK WM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Yn+d!w<3:
nStartPos,nEndPos,i); /t=Fx94
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5S/YVRXq
fileSplitterFetch.start(); q37d:Hp
} x<gP5c>zm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l'm\*=3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z^_-LX:%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \YMe&[C:o
nEndPos = " + nFileLength); DV5K)m&G
// fileSplitterFetch[nPos.length-1].start(); +ebmve \+
aEvW<jHh
kh5VuXpe
//等待子线程结束 7AouiL 2-W
//int count = 0; CA[3R
//是否结束while循环 JK=0juv<E
boolean breakWhile = false; L,7+26XV"B
(5\VOCT>4%
JC#M,j2
while(!bStop) -RKqbfmi=
{ U_.9H _G
write_nPos(); P g.j]
Utility.sleep(500); Bh0hUE
breakWhile = true; 6t!PHA
hgPzx@
4mM?RGWv
for(int i=0;i<nStartPos.length;i++) t,,W{M|E(
{ 6U(MHxY
if(!fileSplitterFetch.bDownOver) .sBwJZ
{ W^8MsdM
breakWhile = false; ,SB5"
break; =,w(D~ps
} EZb_8<DH
} efUa[XO
if(breakWhile) {,Z-GJ
break; TRzL":
$z \H*
+rN&@}Jt.
//count++; ~Kiu" g
//if(count>4) 2R=Fc@MXs
// siteStop(); < ?{ic2j#
} fMluVND
`2l j{N
b-Xc6f
System.err.println("文件下载结束！"); J*nWCL
} /]>8V'e\
catch(Exception e){e.printStackTrace ();} $ts1XIK%
} ,(y6XUV~
HY>zgf,0
?Jy/]j5fI
//获得文件长度 9ymx;
public long getFileSize() W\1V`\gF
{ =tQ^t4_
int nFileLength = -1; 0/TP`3$X#"
try{ ({!S!k
URL url = new URL(siteInfoBean.getSSiteURL()); ~/l5ys
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YDWV=/
httpConnection.setRequestProperty("User-Agent","NetFox"); P,W(9&KM
YQN@;
,9YgznQ
int responseCode=httpConnection.getResponseCode(); &qMt07
if(responseCode>=400) `JzP V/6
{ >j6"\1E+Dz
processErrorCode(responseCode); 0 P2lq
return -2; //-2 represent access is error P+<4w
} :/XWk %
N;mJHr3[F
oa<%R8T?@
String sHeader; M"!{Dx~
h,@tfd U^
5lrjM^E|
for(int i=1;;i++) H63?Erh>a
{ 5[0W+W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,?oC+9w
//Utility.log(in.readLine()); /|LQ?n
sHeader=httpConnection.getHeaderFieldKey(i); h\lyt(.s
if(sHeader!=null) }/J<#}t
{ WWgJ !Uz
if(sHeader.equals("Content-Length")) %*a%F~Ss
{ (U([T-H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Lc! t
break; o>75s#= b=
} M.u1SB0
} mPJ@hr%3
else |YcYWok
break; !$pnE:K
} i#KY'"P
} *6/OLAkyF
catch(IOException e){e.printStackTrace ();} 8/"R&yAh
catch(Exception e){e.printStackTrace ();} WbJ
(MzThGJK_
7!PU}[:
Utility.log(nFileLength); y"Ios:v@-
5a%i%+;N
{&uN q^Ch
return nFileLength; apwA
} F#KUu3;B
r<OqI*7
p>h}k_s
//保存下载信息（文件指针位置） W4&Itj
private void write_nPos() I''X\/|
{ 7Sl"q=>
try{ {xu~Dx
output = new DataOutputStream(new FileOutputStream(tmpFile)); IylfMwLC
output.writeInt(nStartPos.length); #ja6nt8GC
for(int i=0;i<nStartPos.length;i++) &6&$vF65c
{ l&{+3aC:
// output.writeLong(nPos); OICH:(t_
output.writeLong(fileSplitterFetch.nStartPos); MmH(dp+
output.writeLong(fileSplitterFetch.nEndPos); 63HtZ=hO7
} ]FEsN6
output.close(); [vn"r^P
} 4|h>.^
catch(IOException e){e.printStackTrace ();} 8SOfX^;o
catch(Exception e){e.printStackTrace ();} B4t,@,\O
} }iRRf_
/[+qw%>
=|V[^#V
//读取保存的下载信息（文件指针位置） vRMGNz_P7[
private void read_nPos() 4vyJ<b
{ )^7- qy
try{ xp%LXxj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m2v'zJd}g
int nCount = input.readInt(); L*zfZ&
nStartPos = new long[nCount]; 8d[!"lL
nEndPos = new long[nCount]; Cig!3
for(int i=0;i<nStartPos.length;i++) S9{&.[O
{ 6F; |x
nStartPos = input.readLong(); GsiT!OP]y
nEndPos = input.readLong(); U.c~l,5%"
} mk[<=k~
input.close(); ZO&F15$P
} PMZ*ECIJU
catch(IOException e){e.printStackTrace ();} H+npe'm_Z
catch(Exception e){e.printStackTrace ();} 8I<LZ{a10
} `P jS
T854}RX[{
g?{7DI`
private void processErrorCode(int nErrorCode) FF~VV<a
{ 3\j3vcuy
System.err.println("Error Code : " + nErrorCode); '@f#GNRT
} l 9bg
PBb'`PV
DAQozhP8
//停止文件下载 [E;~Y_l
public void siteStop() Dpkc9~z
{ g-<[* nF
bStop = true; 6.6x$y3v
for(int i=0;i<nStartPos.length;i++) CO{AC~
fileSplitterFetch.splitterStop(); V`xE&BI
+m4?a\U
x }i'2
} qkD9xFp
} )TOKHN
//负责部分文件的抓取 'Ooq.jaK;/
**FileSplitterFetch.java r<pt_Cd
*/ XL`i9kV?
package NetFox; # 66vkf*
j1K?QH=e#{
NT<}-^
import java.io.*; i+~H~k}"X
import java.net.*; T#ehJq 5
[='<K
~QU\kZ7Z
public class FileSplitterFetch extends Thread { LsaRw-4.c
X;d 1@G
vg\fBHzn
String sURL; //File URL ?<~P)aVVj
long nStartPos; //File Snippet Start Position wj9Hh
long nEndPos; //File Snippet End Position LEA^o"NW.
int nThreadID; //Thread's ID Y*YV/E.
boolean bDownOver = false; //Downing is over [Y8ot-6
boolean bStop = false; //Stop identical G&#l3bkQ
FileAccessI fileAccessI = null; //File Access interface hSXZu?/
UB7C,:"
^K[[:7Aem
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -9yWf8;
{ PY[!H<tt
this.sURL = sURL; Vc&xXtm[v
this.nStartPos = nStart; M4K>/-9X+V
this.nEndPos = nEnd; NLZUAtx(
nThreadID = id; _SqUPTb"u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 85#+_}#
} ?}<Wmy2A
{oRR]>
Gt;U9k|i
public void run() +?uZ~VSl
{ Kbcr-89Gv~
while(nStartPos < nEndPos && !bStop) O>>%lr|
{ e@L?jBj8m
8[d6 s
q@}tv=}
try{ GL3olKnL
URL url = new URL(sURL); ..yLtqos
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5 0<
httpConnection.setRequestProperty("User-Agent","NetFox"); !KLY*bt6
String sProperty = "bytes="+nStartPos+"-"; A~#w gLGn
httpConnection.setRequestProperty("RANGE",sProperty); -}P/<cu:
Utility.log(sProperty); dgW/5g
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#RP7?yGM,
InputStream input = httpConnection.getInputStream(); Df0m
//logResponseHead(httpConnection); i~.9B7hdE
XZ_vbYTj
qWw{c&{Q],
byte[] b = new byte[1024]; O],]\M{GL
int nRead; 7-[^0qS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;"+]bne~
{ rB.LG'GG]
nStartPos += fileAccessI.write(b,0,nRead); W(jP??up
//if(nThreadID == 1) eG%Q 3h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e*pYlm
} %$zX a%A
dwmZ_m.
#i|AE`
Utility.log("Thread " + nThreadID + " is over!"); o'!WW
bDownOver = true; 5+Hw @CY3
//nPos = fileAccessI.write (b,0,nRead); c8M'/{4rH
} )X5en=[)O
catch(Exception e){e.printStackTrace ();} (kZ2D
} R%)7z)~
} kT4Oal+4
a'YK1QX
UYsyVY`Fm|
//打印回应的头信息 |H4f&&Wd
public void logResponseHead(HttpURLConnection con) Uf<IXx&;
{ H1a<&7
for(int i=1;;i++) Rx.dM_S
{ |gM@}!DL
String header=con.getHeaderFieldKey(i); ]VHO'z\m
if(header!=null) .{66q#.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ugv"A;l
Utility.log(header+" : "+con.getHeaderField(header)); Lb%:u5X\D@
else W3Dtt-)E
break; DeGcS1_?
} ^:,I #]
} "[wP1n!G
T|ZJ$E0
o7t#yw3
public void splitterStop() }XIUz|
{ "78BApjWT6
bStop = true; rWxQ;bb#
} 75RQ\_zDu
Hy#<fKz`!
w$[ck=
} .dl4f"k
`Y.Q{5Y
\,yX3R3}.~
/* kac]Rh8vO
**FileAccess.java 4 X6_p(
*//文件访问(定位，写) F;<cG`|Rx
package NetFox; AJR`ohh
import java.io.*; cj9<!"6
OjBg$f~0F
E~'QC
public class FileAccessI implements Serializable{ >e9xM Gv
gukKa
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4: S-
RandomAccessFile oSavedFile; 3NxwQ,~
long nPos; +G[N lb
Nm,9xq
88M$mjx
public FileAccessI() throws IOException 6@cT;=W;xj
{ Zh3hCxXa
this("",0); }pL#C
} a^.5cJ$]
ad'C&^o5
TaE&8;H#N
public FileAccessI(String sName,long nPos) throws IOException ~t.M!vk
{ 7&{[Y^R]"
oSavedFile = new RandomAccessFile(sName,"rw"); i9quP"<9
this.nPos = nPos; J#jx)K!
oSavedFile.seek(nPos); &/tGT3)
} E>3(ff&
} 2P,Z6L
2]/[
public synchronized int write(byte[] b,int nStart,int nLen) !i*bb~
{ PxiJ R[a
int n = -1; (| X?
try{ )|CF)T-
oSavedFile.write(b,nStart,nLen); kSH|+K\M4
n = nLen; ?(P3ZTk?.
} :igURr
catch(IOException e) V j"B/@
{ ;PF!=8dW
e.printStackTrace (); KI~M.2pk
} n0<I
|%xgob
,]qTJ`J
return n; Gs)2HR@>
} `]3A#y)v
fC^POLn[f
!;~6nYY
} ={gfx;
L>1i~c&V
FT+[[9i
/* Mo_(WSs
**SiteInfoBean.java "0#d F:qt
*/ H:>i:\J/M9
package NetFox; *mTx0sQz(J
1Wy0#?L
N)N\iad^
public class SiteInfoBean { Jx_BjkF
s6| S#
y?*4SLy
private String sSiteURL; //Site's URL |ZuS"'3_w
private String sFilePath; //Saved File's Path ^i!6q9<{e
private String sFileName; //Saved File's Name "~^#{q
private int nSplitter; //Count of Splited Downloading File -=CZhp
U5x&?n<
cop \o4ia
public SiteInfoBean() /R% Xkb
{//nSplitter的缺省值为5 u?+i5=N9{
//default value of nSplitter is 5 K,Z_lP_~Vw
this("","","",5); 3T7,Y(<V
} ;R8pVj!1f
"de3Sbj@?
)T26cT$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) wtpz ef=
{ jizp\%W+
sSiteURL= sURL; B+8B<xZ
sFilePath = sPath; >p|tIST
sFileName = sName; mcFJ__3MAV
this.nSplitter = nSpiltter; x\MzMQ#Bf
xgV(0H}Mf
B6gn(w3
} !w}cKm
l'0fRQc
^B`*4
public String getSSiteURL() FyV)Nmc%t
{ WfF~\DlrD
return sSiteURL; B%Vz -t
} Tz{f5c&
{,`)
Y~%9TC
public void setSSiteURL(String value) oe*Y(T\G
{ 27q=~R}
sSiteURL = value; [~#]p9|L
} ql_GN[c/
uiQRRT
(h3f$
public String getSFilePath() Oj? |g_
{ *8?0vkZZ2
return sFilePath; O${B)C,
} N,M[Opm
LWp#i8,
]= nM|e
public void setSFilePath(String value) TCI%Ox|a
{ 1P[[PvkD6
sFilePath = value; "cVJqW
} K~DQUmU@
] 3UlF'{
g=5vnY
public String getSFileName() XV|u!'Ey
{ 9C_Vb39::$
return sFileName; ;#jE??E/:
} {i09e1
*[SOz)
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public void setSFileName(String value) 48 n5Y~YS
{ gcKXda(
sFileName = value; y.PsC '
} rE[:j2HF
i,z^#b7JQ
B{ptP4As-
public int getNSplitter() VwKo)zH
{ rMy(NAo_
return nSplitter; N&]GPl0
} /+g9C(['
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public void setNSplitter(int nCount) D`e6#1DbJ
{ Svun RUE-f
nSplitter = nCount; Ga M:/.
} j{?ogFfi
} vl,Ff9
3{*nG'@Mal
Q eZg l!
/* e!hy,O{Pw
**Utility.java o$%I{}9x
*/ P/e6b .M
package NetFox; 7)Y0D@wg
gf\F%VmSN
FT$Z8
public class Utility { (n+FEE<
V9%!B3Sb
ZFH;
public Utility() 94CHxv
{ #i1z&b#@
|Y")$pjz
"gCqb;^
} CL)*cu6zG
P1>?crw
//线程睡眠 &4R-5i2a
public static void sleep(int nSecond) ]QJWqY
{ (G<fvl!~
try{ 1@"os[9
Thread.sleep(nSecond); alV{| Vf[6
} WnkIi,<
catch(Exception e) i+&o%nK2
{ =)Z~w`
e.printStackTrace (); L63B# H"
} M?QK4Zxb6U
} |q+dTy_n
1X,\:F.-+
//日志 6Ex16
public static void log(String sMsg) f(Uo?_as
{ RAUD8Z
System.err.println(sMsg); ~M?^T$5
} x3L0;:Fx8P
.2v)x
VTIRkC wl@
public static void log(int sMsg) J7Y lmi
{ Bl1^\[#
System.err.println(sMsg); 4u}jkd$]*
} o_@6R"|
} W#sCvI@
*Q XUy
C=zc6C,
/* XRx^4]c
**TestMethod.java Yj'/ p
*/ hvo7T@*'
package NetFox; u`~,`z^{n
r0L' mf$
H2oD0f|
public class TestMethod { xwjiNJ Gj
*\"+/
W6Z3UJ-
public TestMethod() ;cD&qheDV
{ ///xx/weblogic60b2_win.exe (\o &Gl
try{ <#%kmYSL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4E0 Y=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U0fr\kM
SiteFileFetch fileFetch = new SiteFileFetch(bean); z5q(
fileFetch.start(); c)B <d#
} 9JBVG~m+
catch(Exception e){e.printStackTrace ();} 25wvB@0&
-?Kd[Ma
K^f&+`v6_
} ]rMHO
S>nf]J`
B +<i=w
public static void main(String[] args) gWLhO|y
{ Dxp.b$0t
new TestMethod(); *h)|Ks
} s.j6" Q[W
} ywkyxt
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