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)); [iXi\Ex
} ]c,l5u}A$
for(int i=0;i<nEndPos.length-1;i++) K Dz]wNf
{ O'Am RJ
nEndPos = nStartPos[i+1]; q-uLA&4
} f~v"zT
nEndPos[nEndPos.length-1] = nFileLength; ,#Ln/;
} #}j]XWy
} _M&{^d
P09,P
'W+i[Ep5Q
//启动子线程 @dl<-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \3: L Nt
for(int i=0;i<nStartPos.length;i++) BUV/twU)
{ cyHhy_~R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GM77Z.Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $&Ac5Zo%}
nStartPos,nEndPos,i); A_]D~HH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n8Q* _?Z/
fileSplitterFetch.start(); vQcUaPm\$
} ?}v}U^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m"q/,}DR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N@}gLBf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h\2}875
nEndPos = " + nFileLength); >07shNX
// fileSplitterFetch[nPos.length-1].start(); M!-q}5';
:`;(p{
^}tLnF
//等待子线程结束 r /^'Xj'(
//int count = 0; mUiOD$rO
//是否结束while循环 nc-Qz
boolean breakWhile = false; a&8l[xe1
^b:Xo"q#H
+fkP+RVY
while(!bStop) s5nB(L*Pjp
{ Pb3EnNqYbM
write_nPos(); |E? ,xWN
Utility.sleep(500); ~.FnpMDY
breakWhile = true; j_(?=7Y3g
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jm4)gmC
for(int i=0;i<nStartPos.length;i++) sK#H4y+<
{ hl*MUD,
if(!fileSplitterFetch.bDownOver) eS* *L3
{ ;r%<2(
breakWhile = false; FF8WTuzB+
break; hJ<:-u+yk}
} R !jhwY$
} _ \_3s
if(breakWhile) f>|9 l
break; j`{fB}
)Kxs@F
#&}%70R)
//count++; >s44
//if(count>4) Io2,% !D
// siteStop(); 8TUF w@H%
} i'U,S`L6>
;g&7*1E
YmZC?x_{M2
System.err.println("文件下载结束！"); G,+xT}@wu
} sYl&Q.\q
catch(Exception e){e.printStackTrace ();} bb*c+XN0
} hT\p)w
zwKg
~WzMK
//获得文件长度 ~}epq6L>
public long getFileSize() 3O#~dFnp
{ GU2]/\W*a
int nFileLength = -1; owP6dtd)
try{ o]dK^[/*
URL url = new URL(siteInfoBean.getSSiteURL()); \o0z@Ntq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |}l@w+N3
httpConnection.setRequestProperty("User-Agent","NetFox"); n+v!H O"2u
X*_ SHt
:8GlyN<E
int responseCode=httpConnection.getResponseCode(); E=$7ieW
if(responseCode>=400) 8[vl3C
{ u!hqq^1
processErrorCode(responseCode); Bidqf7v
return -2; //-2 represent access is error 6(\q< fx
} q]2}UuM|U
Sr4dY`V*:z
Uyz;U34 oI
String sHeader; _HSTiJVr
8h55$j
@hE7r-}]
for(int i=1;;i++) kxcgOjrmI
{ E!:.G+SEl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #-l!`\@
//Utility.log(in.readLine()); `HE>%=]b
sHeader=httpConnection.getHeaderFieldKey(i); jB}_Slh1j
if(sHeader!=null) :_W0Af09
{ gvow\9{|C
if(sHeader.equals("Content-Length")) XHU<4l:kl
{ R^n* o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8#[%?}tK
break; AT2NC6{M
} 8 /:X& &
} J"m%q\'
else {s9y@c*15.
break; : OSmr
} Dx9$H++6$X
} | 7t=\
catch(IOException e){e.printStackTrace ();} )Mm;9UA
catch(Exception e){e.printStackTrace ();} sa\|"IkD2
Enq6K1@%G
Gnuo-8lb
Utility.log(nFileLength); u*#-7
GQEIf$
A>rWGo.{E
return nFileLength; EZgxSQaPH
} Pf^Ly97
[wXwKr
/6Jy'"+'0
//保存下载信息（文件指针位置） 3G:NZ)p
private void write_nPos() ,"v)vTt
{ #dxJ#
try{ !W+p<F1i
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6KBzlj0T+
output.writeInt(nStartPos.length); N,'[:{GOY
for(int i=0;i<nStartPos.length;i++) r7]?g~zb
{ mjkw&2
// output.writeLong(nPos); 3Vb=6-|
output.writeLong(fileSplitterFetch.nStartPos); LOyCx/n
output.writeLong(fileSplitterFetch.nEndPos); r1^m#!=B
} 5bGjO&$l
output.close(); J?|K#<%
} yhJA;&}>
catch(IOException e){e.printStackTrace ();} ebl)6C
catch(Exception e){e.printStackTrace ();} q.u[g0h;
} YU ]G5\UU
UIm[DYMS
(}/.4xE
//读取保存的下载信息（文件指针位置） R-2FNl
private void read_nPos() ,YAPCj
{ d~P<M3#>
try{ i_jax)m%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #NVF\
int nCount = input.readInt(); =:v><
nStartPos = new long[nCount]; VDb,$i.Z0
nEndPos = new long[nCount]; 8VAYIxRv
for(int i=0;i<nStartPos.length;i++) T9U2j-lA?
{ E9Qd>o
nStartPos = input.readLong(); D:RBq\8
nEndPos = input.readLong(); u+I r:k
} /w}B07.
input.close(); D=q;+,Pc
} O[5_9W 4
catch(IOException e){e.printStackTrace ();} N c&i) qh
catch(Exception e){e.printStackTrace ();} y.ivz
} &?5{z\;1"
6S&=OK^
9wDBC~.
private void processErrorCode(int nErrorCode) u]>>B>KOJ7
{ :<WQ;q
System.err.println("Error Code : " + nErrorCode); I!soV0VU]
} :+?W
yjM@/b
08d_DCR
//停止文件下载 "`$'tk[
public void siteStop() 7/U<\(V!g
{ s&QBFyKtJ
bStop = true; &Curvc1fm
for(int i=0;i<nStartPos.length;i++) 7KSGG1ts
fileSplitterFetch.splitterStop(); n'&`9M['%d
W2W2WyPk
U_ ?elz\
} 3A}nNHpN
} #ejw@bd
//负责部分文件的抓取 -'p@ lk
**FileSplitterFetch.java 5M\=+5wB
*/ 9,EaN{GM
package NetFox; EV?47\~
R6WgA@Z|r
#@\NdW\
import java.io.*; UmD-7Fd
import java.net.*; :z0>H5
K9qEi{[
c!u}KVH
public class FileSplitterFetch extends Thread { p,AD!~n`
o"ah\"#el
:@@A
String sURL; //File URL @gqs4cg{f
long nStartPos; //File Snippet Start Position 7U[L\1zS
long nEndPos; //File Snippet End Position `2mbF^-4
int nThreadID; //Thread's ID R;TEtu7
boolean bDownOver = false; //Downing is over EAd:`X,Y
boolean bStop = false; //Stop identical /E4}d=5L
FileAccessI fileAccessI = null; //File Access interface `TlUJ]d)
sQw`U{JG
F)5B[.ce
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException if!`Qid
{ PSQ:'
this.sURL = sURL; ,fG_'3wb
this.nStartPos = nStart; .iN*V|n
this.nEndPos = nEnd; }B '*8^S
nThreadID = id; 'iISbOM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C.B}Py+
} \;:@=9`
73z|'0.
qD%&\ZT
public void run() y" 6~9j
{ 5<?c_l9X^
while(nStartPos < nEndPos && !bStop) i`nw"8
{ 9H%xZ(`vN
8!%"/*P$
n25tr'=
try{ OUk5c$M(
URL url = new URL(sURL); U>-#('
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fQ.>G+0I>
httpConnection.setRequestProperty("User-Agent","NetFox"); Cbg#Yz~/
String sProperty = "bytes="+nStartPos+"-"; p+sPCF
httpConnection.setRequestProperty("RANGE",sProperty); @$yYljP
Utility.log(sProperty); hG;=ci3EE
.QQI~p0:
c2mt<DtWW
InputStream input = httpConnection.getInputStream(); Bpo68%dx89
//logResponseHead(httpConnection); |j}F$*SE[
Y9L6W+=T
N_k6UA9
byte[] b = new byte[1024]; UR2)e{RXg
int nRead; *#^1rKGWK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u\geD
{ \J:T]
nStartPos += fileAccessI.write(b,0,nRead); ~d `4W<1a
//if(nThreadID == 1) ;GT)sI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jb.u^3R@
} Ib8{+j
khIa9Nm
ViT 5Jn7
Utility.log("Thread " + nThreadID + " is over!"); >@Vr'kg+V
bDownOver = true; [=F |^KL
//nPos = fileAccessI.write (b,0,nRead); htrj3$q(4
} 6SO7iFS
catch(Exception e){e.printStackTrace ();} 6%INNIyAWa
} }Q^a.`h
} .);:K
O:p649A
dTQvz9C
//打印回应的头信息 A":b_!sW
public void logResponseHead(HttpURLConnection con) >D4Ez
{ 6jo&i
for(int i=1;;i++) B]F7t4Y!
{ FF!g9>
String header=con.getHeaderFieldKey(i); qML*Kwg
if(header!=null) .%Q Ea_\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,4W((OQ^
Utility.log(header+" : "+con.getHeaderField(header)); $[CA#AXE
else 5@%-=87S
break; 5m?$\h
} j:KQIwc
} gK\7^95
ZKPkx~,U[
S)|b%mVwR
public void splitterStop() oz-I/g3go
{ :=eUNH
bStop = true; 8vW`E_n
} 0%NI- Zyo
VDY1F_Fk
)_K@?rWS
} !QS<;)N@
'\\Cpc_g
PuCA @qY
/* Ka\b_P&
**FileAccess.java QXj(U&#rp
*//文件访问(定位，写) }3y\cv0ct
package NetFox; 4PM`hc
import java.io.*; :?k=Yr
lFY8^#@
yLOLv6g~e
public class FileAccessI implements Serializable{ "<a|Q,!
&ru0i@?)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !T. @
RandomAccessFile oSavedFile; }*R6p?L5
long nPos; ye2Oh7
z1s"C[W2T
jloyJ@ck
public FileAccessI() throws IOException |R/50axI
{ dwMwd@*j
this("",0); mP[u[|]
} 8:fiO|~%
9(j!#`O7&
@ RBwT
public FileAccessI(String sName,long nPos) throws IOException hz<J8'U
{ e*s{/a?,
oSavedFile = new RandomAccessFile(sName,"rw"); V1A3l{>L
this.nPos = nPos; nTKfwIeg5
oSavedFile.seek(nPos); NLY5L7
} 3vU (4}@
B4aZ3.&W
3: Uik
public synchronized int write(byte[] b,int nStart,int nLen) #KW:OFT
{ sc60:IxgI
int n = -1; =YIQ _,{u
try{ E:k?*l
oSavedFile.write(b,nStart,nLen); yk{alSF
n = nLen; .vMi<U;
} I&Y(]S,cU
catch(IOException e) 3(5Y-.aK}^
{ {eUfwPAa3
e.printStackTrace (); 6<Z9p@6
} e.V){}{V
|e&Kg~~C
EA.U>5Fq
return n; &=bI3-
} 2-84
vNGvEJ`qn
J~.kb k
} G\%hT5^
6! 'Xo:p
W6Pg:Il7
/* _8 J(;7
**SiteInfoBean.java >kYyR.p.b
*/ :xCobMs_/
package NetFox; ny=iAZM>q
F1>,^qyG6
^ a:F*<D
public class SiteInfoBean { kx[8#+P
E<dN=#f6
&&O=v]6,V
private String sSiteURL; //Site's URL y1X.Mvc
private String sFilePath; //Saved File's Path ~_%[j8o&l
private String sFileName; //Saved File's Name pG&.Ye]j
private int nSplitter; //Count of Splited Downloading File M .,|cx
UlrY
FhGbQJ?[3
public SiteInfoBean() rNc>1}DDS
{//nSplitter的缺省值为5 2lRZ/xaF%P
//default value of nSplitter is 5 {y'kwU
this("","","",5); dyd_dK/
} 7(H/|2;-d8
zYgLGwi{
GcuZPIN%D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >nX'RE|F
{ EcU9Tm`h
sSiteURL= sURL; wal }[F#
sFilePath = sPath; Sgj6tH2M
sFileName = sName; }_ E
this.nSplitter = nSpiltter; ]7;;uhn`
']Z8C)tK
xpz Jt2S
} P}gh-5x
#LiC@>
RMXP)[
public String getSSiteURL() ^d,d<Uc
{ 6]VTn-
return sSiteURL; iYnt:C
} x>cu<,e$d\
k4v[2y`
',f[y:v;
public void setSSiteURL(String value) V6Y!0,w!a
{ bGZy0.
sSiteURL = value; L6T_&AiL$
} sZc<h]L(g
Y%3j>_\;
D%zIm,bf
public String getSFilePath() ",a fv{C
{ PyYe>a;.
return sFilePath; Wxjpe4
} v!2`hqO
"2mVW_k
F>OYZOC]
public void setSFilePath(String value) 7DDot_qb
{ kDsUKO p
sFilePath = value; #]rw@c
} Ab`Gb
#ed]zI9O
6*$N@>8&
public String getSFileName() _wIAr
{ fw<'ygd
return sFileName; ^#+9v
} /=%4gWtr
>|<6s],v
J{H475GqiT
public void setSFileName(String value) /9sUp}*
{ m35G;
sFileName = value; ZP1EO Z
} ws=y*7$y
Mvux=Ws
H_9~gi
public int getNSplitter() tZJKB1#WbP
{ sB $!X@
return nSplitter; !*p lK6a
} :H~r _>E
!)GPI?{^5
\>+gZc]an
public void setNSplitter(int nCount) =Oy,SX
{ bbz86]AhY
nSplitter = nCount; #C|iW@
} p?Y1^/
} 3'8~H]<W
7\.5G4dr%
[*Lh4K
/* S5j#&i
**Utility.java + EM '-
*/ 7Ev~yY;N
package NetFox; d%WFgf}
>6Q-e$GS@
\o/oM,u
public class Utility { PWTAy\
d<y B ~Y
fSj^/>
public Utility() f.!cR3XgV
{ 74Lq!e3hMF
h-<+Pjc
qu?D`29
} t JJaIb6Xj
5z0SjQ
//线程睡眠 by-B).7
public static void sleep(int nSecond) b(wiJ&t
{ 'i}Q R~pe
try{ x,n;GR
Thread.sleep(nSecond); 8ED6C"6
} wuPx6hCl
catch(Exception e) \5Hfe;ny-~
{ 'Ic$p>
e.printStackTrace (); 'C(YUlT2?P
} X4jtti
} #U^@)g6
X"yLo8y8$
//日志 dD=dPi#
public static void log(String sMsg) q?`bu:yS
{ 0 ~VniF^
System.err.println(sMsg); By" =]|Q
} }_K7}] 1
JD.WH|sZ5
?>2k>~xlQ
public static void log(int sMsg) hW(Mf
{ m!g f!
System.err.println(sMsg); lOql(ZH`w
} !iMsTH<
} 5@?P8
%|UCs8EFm
(R{WJjj
/* )nQ.6
**TestMethod.java cO' \s
*/ fxjs"rD5
package NetFox; %{axoGd
WUKYwA/t
ri6_u;Ch
public class TestMethod { TeQpmhN
geua8;
^MuO;<<,.
public TestMethod() H.*XoktC]
{ ///xx/weblogic60b2_win.exe _E3*;
try{ *U8Pjb1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y7= *-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4\3Z$%2^LZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); G >bQlZG
fileFetch.start(); LXrnAt
} JW (.,Ztm
catch(Exception e){e.printStackTrace ();} >osY?9
+[ !K
LyH{{+V
} \It8+^d@
F8f@^LVM/
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public static void main(String[] args) &0~E+ 9b
{ 8ex{N3
new TestMethod(); Hr:WE+'
} LNtBYdB`pK
} iCnKQG
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