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)); lFV N07hG
} $ us]35Z3
for(int i=0;i<nEndPos.length-1;i++) Af'" 6BS
{ ]v]qChZHd
nEndPos = nStartPos[i+1]; 7|$:=4
} ~,oMz<iMV
nEndPos[nEndPos.length-1] = nFileLength; 3c]b)n~Y
} )GM41t1i
} [BqHx5Xz(
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r0+6evU2
//启动子线程 SEGri#s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @,cowar*
for(int i=0;i<nStartPos.length;i++) P(,p'I;j
{ DVB{2~7 4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ['B?i1 .
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &:dH,
nStartPos,nEndPos,i); Q;43[1&3w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <b`E_
fileSplitterFetch.start(); rA5=dJ"I
} x7jC)M<k0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rn9m]x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (`c [#0=n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -bT)]gA2
nEndPos = " + nFileLength); %yW3VL
// fileSplitterFetch[nPos.length-1].start(); D(AXk8Vub
C/vIEYG4
i+S) K
//等待子线程结束 YW_Q\|p]M
//int count = 0; 1m:XR0P
//是否结束while循环 aTqd@},?
boolean breakWhile = false; V )x$|!(
'B 43_
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while(!bStop) \]2]/=2tLd
{ #Ssx!+q?
write_nPos(); mpuq 9)6
Utility.sleep(500); <`B,R*H{
breakWhile = true; :D%"EJ
Lvq>v0|
GT}F9F~
for(int i=0;i<nStartPos.length;i++) 6@{(;~r
{ LcSX*MC
if(!fileSplitterFetch.bDownOver) }L+L"l&
{ h]5C|M|
breakWhile = false; #h8Sq~0
break; v/68*,z[
} j53*E )d
} zr+zhpp
if(breakWhile) LcB]Xdsa(
break; 5_I->-<
b&~4t/Vq
]b7zJUz
//count++; 6K-_pg]
//if(count>4) r@+ri1c
// siteStop(); OWjk=u2Lz
} p?7v$ev_
ftvG\Tf
~sl{|E
System.err.println("文件下载结束！"); 2Ga7$q
} =BSzsH7
catch(Exception e){e.printStackTrace ();} "a ueL/dgN
} `\T]ej}zvI
\>:CvTzF
x(etb<!jd
//获得文件长度 -:2$ %
public long getFileSize() dJ2Hr;Lc
{ >/kcdWl
int nFileLength = -1; 9[b<5Llt
try{ Q[vJqkgT
URL url = new URL(siteInfoBean.getSSiteURL()); wRcAX%n&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Kwefs;<E?
httpConnection.setRequestProperty("User-Agent","NetFox"); \Xm,OE_v"
WQ[_hg|k
s2'yY(u/
int responseCode=httpConnection.getResponseCode(); q>$ev)W
if(responseCode>=400) ,SynnE68
{ iYORu3
processErrorCode(responseCode); < Z{HX[y
return -2; //-2 represent access is error L;VoJf
} Co (.:z~
iop2L51eJ
C([phT;
String sHeader; 3L833zL
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*.sVr7=j
for(int i=1;;i++) 3 Nreqq
{ 42e|LUZg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WG6FQAo^8
//Utility.log(in.readLine()); W-x?:X<}
sHeader=httpConnection.getHeaderFieldKey(i); \ e\?I9
if(sHeader!=null) {QcLu"?c
{ Qy^1*j<@&
if(sHeader.equals("Content-Length")) 4L ;% h
{ -=)+dCyB^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E*.{=W }C
break; e,F1Xi#d
} \>jLRb|7Ts
} (]0%}$Fo
else 4}_j`d/8|
break; uw[<5
} *5vV6][
} _LMM,!f
catch(IOException e){e.printStackTrace ();} LR.Hh
catch(Exception e){e.printStackTrace ();} TH; R
& -{DfNKc
]h>_\9qO
Utility.log(nFileLength); %\D)u8}
ud xZ0
^B(V4-|
return nFileLength; Bt>}rYz1
} LJk@Vy <?
WM| dKF
|uqf:V`z:
//保存下载信息（文件指针位置） eqP&8^HP
private void write_nPos() "^w]_^GD$d
{ 0vEoGgY0*:
try{ vy0X_DPCr
output = new DataOutputStream(new FileOutputStream(tmpFile)); LQ(yScA@
output.writeInt(nStartPos.length); [s"O mAy4
for(int i=0;i<nStartPos.length;i++) &<wuJ%'>)Z
{ QW$G
// output.writeLong(nPos); ;3d"wW]}7K
output.writeLong(fileSplitterFetch.nStartPos); FME3sa$
output.writeLong(fileSplitterFetch.nEndPos); ofPHmh`
} S0~2{G"v
output.close(); =NnNN'}
} m@"QDMHk.
catch(IOException e){e.printStackTrace ();} #JgH}|&a$
catch(Exception e){e.printStackTrace ();} W%T>SpFl
} 73V|6tmgY
q}~3C1
?&|5=>u2}$
//读取保存的下载信息（文件指针位置） q*F{/N**
private void read_nPos() dRj|g
{ .q%WuQw
try{ B8B; y^b>i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b4E:Wn9x
int nCount = input.readInt(); lV1G<qP
nStartPos = new long[nCount]; [`^a=:*
nEndPos = new long[nCount]; ,_Z5m;
for(int i=0;i<nStartPos.length;i++) POdUV
{ }\HN&@
nStartPos = input.readLong(); &>%T^Y|J4
nEndPos = input.readLong(); SnE(o)Q
} aa>xIW,u
input.close(); >#hO).`C
} FN\E*@>X=
catch(IOException e){e.printStackTrace ();} 4 !y%O
catch(Exception e){e.printStackTrace ();} h3bff#<K
} cWi}V
T(f/ ?_%
Po ZuMF
private void processErrorCode(int nErrorCode) -u2P ?~
{ SS$[VV
System.err.println("Error Code : " + nErrorCode); Qa.<K{m#?
} EQf[,
(iL|Sq&}b
[x9KVd ^d
//停止文件下载 1+9W+$=h2
public void siteStop() POvP]G9'"
{ wQe_vY
bStop = true; Pa~)"u8
for(int i=0;i<nStartPos.length;i++) W#KpPDgZE
fileSplitterFetch.splitterStop(); `Jzp Sw
*MJX?
_59huC.
} kPVO?uO
} LL2=&VK
//负责部分文件的抓取 lrv3fPIW
**FileSplitterFetch.java -amBB7g
*/ A9wh(P0\
package NetFox; !q9+9 *6
Zn ''_fjh
5[A@gw0u
import java.io.*; ~ vJ,`?
import java.net.*; N'g>MBdI
c2&q*]?l;
lEhk'/~
public class FileSplitterFetch extends Thread { R $&o*K`?
K Pt5=a
p(~Yx3$*
String sURL; //File URL i(iXD
long nStartPos; //File Snippet Start Position "f "6]y
long nEndPos; //File Snippet End Position 0URji~?|x
int nThreadID; //Thread's ID c&AygqN
boolean bDownOver = false; //Downing is over (CsD*U`h
boolean bStop = false; //Stop identical qMLD)rL
FileAccessI fileAccessI = null; //File Access interface dR"@`
d5oIH
Y8o)FVcyNy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Qk,I^1w?7
{ ch0{+g&
this.sURL = sURL; t0IEaj75c
this.nStartPos = nStart; <-[wd.M_
this.nEndPos = nEnd; pov)Z):}G<
nThreadID = id; gLy&esJl1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m06ALD_
} a'2$nbp}
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k&,~qoU
public void run() Q aS\(_
{ G&4&-<
while(nStartPos < nEndPos && !bStop) sOU1n
{ !"\80LP
J[4mLU
K#pNec
try{ \=6l9Lrj>h
URL url = new URL(sURL); &ge "x{,?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4scNSeW
httpConnection.setRequestProperty("User-Agent","NetFox"); i[?Vin
String sProperty = "bytes="+nStartPos+"-"; >AcrG]
httpConnection.setRequestProperty("RANGE",sProperty); ^-,xE>3o
Utility.log(sProperty); y#q?A,C@n
4<k9?)~(J
K%^V?NP*{Z
InputStream input = httpConnection.getInputStream(); #MRMNL@
//logResponseHead(httpConnection); %`&2+\`
,M^P!
l]8D7(g
byte[] b = new byte[1024]; m+lvl
int nRead; UE$UR#T'w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q0&H#xgt
{ cVv;Jn
nStartPos += fileAccessI.write(b,0,nRead); p$PKa.Y3
//if(nThreadID == 1) 0cJWJOj&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O"F_*
} k3)dEH1z
mg*qiScfW
UFp,a0|
Utility.log("Thread " + nThreadID + " is over!"); oxz OA
bDownOver = true; A'jP7P
//nPos = fileAccessI.write (b,0,nRead); joiL{
} 2oNk93D
catch(Exception e){e.printStackTrace ();} wid;8%m
} rvXWcu-"
} K95p>E`9e
">y%iE
[Pq}p0cD
//打印回应的头信息 yIDD@j=l
public void logResponseHead(HttpURLConnection con) J6L K
{ DX"xy
for(int i=1;;i++) p2DrEId
{ .ys6"V|31
String header=con.getHeaderFieldKey(i); 9983aFam
if(header!=null) ?e,pN,4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >hk=VyU;
Utility.log(header+" : "+con.getHeaderField(header)); )u/yF*:n
else 6^%68N1k
break; HN&Z2v
} FRg^c kb"
} l}]t~!X=
5[* qi?w=
S$Q8>u6Wk
public void splitterStop() v?& -xH-S
{ 763v
bStop = true; :9$F'd\
} BV>\ McI+
PDrZY.-
=gJb^ Gx(w
} ,'p2v)p^4
$`z)~6'
(UU(:/
/* iy14mh\ ~
**FileAccess.java A7%:05
*//文件访问(定位，写) t4-pM1]1_
package NetFox; f"u%J/e&
import java.io.*; W!6qqi{
.)<(Oj|4
{`K m_<Te!
public class FileAccessI implements Serializable{ QrYpZZ;
'J6 M*vO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D(h18
RandomAccessFile oSavedFile; YEj8S5"Su\
long nPos; X!m9lV<
20Z8HwQi
b#K:_ac5
public FileAccessI() throws IOException O'W0q;rT
{ Y@b.sMg{
this("",0); l)!n/x_ !
} 8erSt!oM
!!`!|w
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public FileAccessI(String sName,long nPos) throws IOException /)4I|"}R0I
{ _g~qu [1
oSavedFile = new RandomAccessFile(sName,"rw"); |b|&XB_<]Z
this.nPos = nPos; )*,5"CO
oSavedFile.seek(nPos); k[HAkB \{
} xYhrO
j{Txl\D>
8AnP7}n;?'
public synchronized int write(byte[] b,int nStart,int nLen) `.x Fiyc
{ A@sZ14+f
int n = -1; |m80]@>
try{ XI9js{p
oSavedFile.write(b,nStart,nLen); uwjGDw
n = nLen; `kU/NKq
} A` AaTP
catch(IOException e) Dg} Ka7H
{ 69J4=5lX
e.printStackTrace (); nSkPM5\TI
} qUOKB6
x}Aw)QCh+r
aEWWFN
return n; 4(1(e
} ;~\MZYs3m
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} "Q?k'^@
l"2OP6d
`g6h9GC6
/* uvV;Mlo]
**SiteInfoBean.java e}.^Tiwd]
*/ &'DU0c&
package NetFox; ngat0'oa
H8`(O"V
iTV) NsC}
public class SiteInfoBean { $pFo Rv
Q~j`YmR|
bf!M#QOk?
private String sSiteURL; //Site's URL FDv+*sZ
private String sFilePath; //Saved File's Path ijdXU8
private String sFileName; //Saved File's Name <F.Tx$s
private int nSplitter; //Count of Splited Downloading File Ns[ym>x#2
S}ECW,K
]f_6 '|5A
public SiteInfoBean() 9>g,
{//nSplitter的缺省值为5 W"k8KODOY
//default value of nSplitter is 5 Ce")[<:
this("","","",5); H03jDM8Q
} &ZX{R#[L
%B)6$!x
IrWD%/$H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^-[?#]
{ gW1b~( fD
sSiteURL= sURL; %0mMz.f
sFilePath = sPath; vJU*>U,
sFileName = sName; K a(J52
this.nSplitter = nSpiltter; #~.w&~:
!Wy[).ZAf
O=dJi9;`#_
} A6pjRxg
y:vxE8$Q
f}@jFhr'<
public String getSSiteURL() (<Th=Fns?
{ =pk)3<GwF
return sSiteURL; <@Fy5k-%.
} N]<!j$pOz
{s_+?<l
Gsc\/4Wx
public void setSSiteURL(String value) Z+StB15
{ 3:f[gV9K
sSiteURL = value; r@o6voX
} 0`I-2M4F*Q
Iy.rqc/86
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public String getSFilePath() pOrWg@<\L
{ ,s_T pq
return sFilePath; OHflIeq#@
} H=\!2XS
)5.C]4jol
L:k9#6
public void setSFilePath(String value) ph#tgLJ
{ `)Z!V?&!
sFilePath = value; JB&\i#
} vQa'S-@u
<6G11-K
?"KC-u|
public String getSFileName() w1|A5q'M
{ f*24)Wn<
return sFileName; l?q%?v8
} %Jf<l&K.`
}h}<!s
7oR:1DXw|
public void setSFileName(String value) ) 9oH,gZ
{ \AC|?/sH
sFileName = value; brZ sAQ+k
} S#-tOjU*
F5 ]C{
Z-B%'/.
public int getNSplitter() v*qQ?S
{ <uc1D/~^:
return nSplitter; B:\Uw|Mf
} }=2;
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PDLpNTBf
public void setNSplitter(int nCount) {h KjD"?
{ ?9X&tK)E-
nSplitter = nCount; xwH?0/
} 7'-j%!#w
} pW]4bx@E
x+@&(NMP5
%,iIpYx
/* 5c;h&
**Utility.java 7E@+
*/ a@pz*e
package NetFox; tdF9NFMD
4\&
m"9XT)N
public class Utility { $) 5Bf3P0
2nFy`|aA%
fN "tA
public Utility() lI/0:|l
{ 4"vaMa
gs W0
}N*>QR5K
} '?Jxt:<
CZEW-PIhj
//线程睡眠 ZCg`z
public static void sleep(int nSecond) s6}Xt=j
{ a0*2) uL}
try{ pAu72O?
Thread.sleep(nSecond); ~=Ncp9ej#
} !%Y~~'5 h
catch(Exception e) C`'W#xnp1
{ i%#$*
e.printStackTrace (); \NqEw@91B
} - /c7nF
} SjdZyJa
.!}hhiF,Z
//日志 ]=!P(z|
public static void log(String sMsg) p$k\m|t
{ 111D3
System.err.println(sMsg); Y1dVM]l
} *wV[TKaN
lr2rQo>
LihjGkj\g
public static void log(int sMsg) y>\S@I
{ gNx+>h`AF
System.err.println(sMsg); 4UAvw
} 9B)(>~q
} CT d|`
X;!D};;M
$gMCR b,
/* H0*5_OJ!i
**TestMethod.java yW.COWL=)
*/ ^t[HoFRa
package NetFox; *wi}>_\
d \>2
Icp0A\L@
public class TestMethod { '9J|=z9.
e@F|NCQ.9
W>spz~w%j
public TestMethod() 0>!/rR7
{ ///xx/weblogic60b2_win.exe v&3O&y/1v
try{ ,f: jioY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :k46S<RE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oj}"H>tTp
SiteFileFetch fileFetch = new SiteFileFetch(bean); )qPSD2h
fileFetch.start(); F?Or;p5`Y
} U '[?9/T
catch(Exception e){e.printStackTrace ();} 9e<Zgr?N
wAbp3hX
)Mzt3u
} JatHSW7j9
EaS~`
\Kd7dK9&]
public static void main(String[] args) dmR3Y.\jd
{ t ,qul4y}
new TestMethod(); dDKqq(9(`
} Kla:e[{
} Q:S\0cI0
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