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)); Y}'C'PR
} i;*c|ma1>
for(int i=0;i<nEndPos.length-1;i++) zC!]bWsD
{ tc\LK_@$/F
nEndPos = nStartPos[i+1]; )-|A|1Uo
} IV;juFw}G
nEndPos[nEndPos.length-1] = nFileLength; :ZL;wtT
} \`jFy[(Pa'
} !tv3.:eT
<<LmO-92
n_AW0i.
//启动子线程 !V$nU8p|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s ,\w00-:
for(int i=0;i<nStartPos.length;i++) [nn/a?Z4S
{ ?c"No|@+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G{}E~jDi?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NwD*EuPF:
nStartPos,nEndPos,i); N+\#k*n?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jpZX5_o
fileSplitterFetch.start(); 9z\q_0&i
} !Qjpj KRy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 511^f`P<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kf_s.Dedw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }lML..((1
nEndPos = " + nFileLength); 7'7bIaJk
// fileSplitterFetch[nPos.length-1].start(); NS-u,5Jt
Ud^+a H
{z|0Y&>[=
//等待子线程结束 2W|4
//int count = 0; }fZT$'*;
//是否结束while循环 ,AGK O,w
boolean breakWhile = false; =r3Yt9
g$ZgR)q
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while(!bStop) LpaY Md;
{ a36n}R4Q
write_nPos(); k7>*fQ89@
Utility.sleep(500); 6.~HbN
breakWhile = true; .hn{m9|U
pnca+d
n7 4?W
for(int i=0;i<nStartPos.length;i++) muT+H(Zp}
{ `5<
if(!fileSplitterFetch.bDownOver) UY*Hc
{ ktU98Bk]
breakWhile = false; Sq/M %z5'
break; ml.l( 6A
} iBwl(,)?m2
} s#&jE GBug
if(breakWhile) kR7IZo"q
break; ~e{AgY)
.Di+G-#aEs
g~h`wv'
//count++; '`T.K<
//if(count>4) aWm0*W"(@
// siteStop(); YNn,{Xi
} u]@``Zb|
JMuUj_^}7
/XEcA5C<
System.err.println("文件下载结束！"); eg~$WB;1
} vlw2dY@^
catch(Exception e){e.printStackTrace ();} (-(,~E
} 6|X
+>KWYPH
U&C\5N]
//获得文件长度 z(g4D!
public long getFileSize() j^llO1i/
{ |q^e&M<
int nFileLength = -1; rVzjLkN^
try{ }EE
URL url = new URL(siteInfoBean.getSSiteURL()); #~I%qa"_pa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [ 8N1tZ{`
httpConnection.setRequestProperty("User-Agent","NetFox"); "}*P9-%
,@R~y
?CAP8_
int responseCode=httpConnection.getResponseCode(); Jh{(xGA
if(responseCode>=400) SLSJn))@!
{ L q'*B9
processErrorCode(responseCode); ?#ndMv!$
return -2; //-2 represent access is error ZL#4X*zT
} L;Nz\sJ
#?}k0Y
+I/7eIG?|
String sHeader; ~d/Doi
j8M}*1
$Etf'.
for(int i=1;;i++) RSG4A>%!mI
{ bnWIB+%_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^>.?kh9z
//Utility.log(in.readLine()); MM|&B`v@;
sHeader=httpConnection.getHeaderFieldKey(i); o(]kI?`
if(sHeader!=null) NAZxM9
{ f6PXcV
if(sHeader.equals("Content-Length")) W~.1f1)
{ *1ekw#'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /_xwHiA
break; mdypZ1f_
} Y{1IRP?S
} 0+P_z(93?
else {K*l,U
break; ZajQ B
} sw'20I
} |bi"J;y
catch(IOException e){e.printStackTrace ();} 09_3`K.*
catch(Exception e){e.printStackTrace ();} !R//"{k0?
y,DK@X
"6Nma)8
Utility.log(nFileLength); j()_ VoB1
M< *5Y43
U.crRrN
return nFileLength; _;yp^^S
} m qPWCFP
7{D+\i
o83HR[
//保存下载信息（文件指针位置） ym2\o_^(
private void write_nPos() -qs.'o ;2
{ 5f=e JDo=x
try{ FxKH?Rl
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7xVI,\qV
output.writeInt(nStartPos.length); bo$xonV@y
for(int i=0;i<nStartPos.length;i++) b}9K"GT
{ M86v
// output.writeLong(nPos); @_FL,AC&m
output.writeLong(fileSplitterFetch.nStartPos); |5F]y"Nb
output.writeLong(fileSplitterFetch.nEndPos); []1VD#
} RA+Y./*h
output.close(); CP7Zin1S/w
} AXH4jQw
catch(IOException e){e.printStackTrace ();} *;m5^i<,;S
catch(Exception e){e.printStackTrace ();} xHJ+!
} /6gqpzum4
\hc}xy 0
JR$Dp&]I
//读取保存的下载信息（文件指针位置） 'hVOK(o0
private void read_nPos() :?RooJ~#
{ 3.Ni%FF`
try{ ORv[Gkq_N)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); er+m:XuV
int nCount = input.readInt(); XsQ<yeun
nStartPos = new long[nCount]; Y%^&aacZ
nEndPos = new long[nCount]; =5oFutg`
for(int i=0;i<nStartPos.length;i++) }dAb}0XK.
{ 1#(,Bq4
nStartPos = input.readLong(); 2OAh7'8<
nEndPos = input.readLong(); "%A/bv\u
} [LL"86D
input.close(); zO9$fU
} 9C-F%te7
catch(IOException e){e.printStackTrace ();} "2'nLQ""q
catch(Exception e){e.printStackTrace ();} d7It}7@9
} W2%(a0p
VpWax]'
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private void processErrorCode(int nErrorCode) [9z<*@$-
{ bNevHKS
System.err.println("Error Code : " + nErrorCode); ^+mSf`5
} Nq9Qsia&
G+m|A*[>
A}~hc&J
//停止文件下载 h[C!cX
public void siteStop() yf3%g\k
{ yIXM}i:
bStop = true; ^(N+s?
for(int i=0;i<nStartPos.length;i++) .2.$Rq
fileSplitterFetch.splitterStop(); feIAgd},
wx}\0(]Gl
BtBy.bR
} f|Z3VS0x
} >f'nl
//负责部分文件的抓取 ^-~.L: }q
**FileSplitterFetch.java q_OIzZ@
*/ /w_Sc{
package NetFox; R@=ve %a-
Rk"VFe>r
[jDO8n/
import java.io.*; #ZCgpg$wM
import java.net.*; }C2I9Cl
K\IS"b3X
KP_=#KD
public class FileSplitterFetch extends Thread { H#m)`=nZSZ
7Q0M3m
Q7"KgqpQ3
String sURL; //File URL .Z8 x!!Q*
long nStartPos; //File Snippet Start Position udp&U+L
long nEndPos; //File Snippet End Position ]v rpr%K
int nThreadID; //Thread's ID 3hO`GM
boolean bDownOver = false; //Downing is over WE|L{
boolean bStop = false; //Stop identical P6i4Dr
FileAccessI fileAccessI = null; //File Access interface gLl?e8[F
pF K[b
z+PSx'#}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _f|Au`7m
{ DcSL f4A
this.sURL = sURL; C(?>l.QGw
this.nStartPos = nStart; ;)0vxcMB
this.nEndPos = nEnd; kQ.atr`?e
nThreadID = id; EVgn^,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T"kaOy
} mRj-$:}L
rU< H7U
x:xKlPGd
public void run() Ad@))o2
{ eff6=DP
while(nStartPos < nEndPos && !bStop) ^._)HM
{ ~UK) p;|
fR6ot#b
:Q+rEjw+
try{ 9VV
URL url = new URL(sURL); MukPY2[Am
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z>o;Yf[
httpConnection.setRequestProperty("User-Agent","NetFox"); |WXu;uf$.u
String sProperty = "bytes="+nStartPos+"-"; >5/dmHPc
httpConnection.setRequestProperty("RANGE",sProperty); o[+1O
Utility.log(sProperty); v :6`(5
$'L(}gNv5
$aE%W? \
InputStream input = httpConnection.getInputStream(); lk6mu
//logResponseHead(httpConnection); <~"qz*_
T-fW[][&$
4{CVBowi
byte[] b = new byte[1024]; 9m!4U2N,s
int nRead; u\Fq\_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _m3PAD4
{ s,K @t_J
nStartPos += fileAccessI.write(b,0,nRead); (mt,:hX
//if(nThreadID == 1) [g=yuVXNZZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fU>"d>6!S
} $o/?R]h
Z=825[p
VG2TiR1
Utility.log("Thread " + nThreadID + " is over!"); ;]Y.2 J
bDownOver = true; ZS>}NN
//nPos = fileAccessI.write (b,0,nRead); k-e_lSYk&c
} /Wg$.<!5}
catch(Exception e){e.printStackTrace ();} g@MTKqs
} G A2S
} egx(N <
e_k1pox]l
E^A9u |x
//打印回应的头信息 +c}fDrr)
public void logResponseHead(HttpURLConnection con) T>vHZZiO
{ Nf-IDK
for(int i=1;;i++) 9y.C])(2
{ {(ey!O
String header=con.getHeaderFieldKey(i); +s1+;VUs3
if(header!=null) /LuwPM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jTSw0\}
Utility.log(header+" : "+con.getHeaderField(header)); *ubLuC+b
else 9g^@dfBV
break; :#d$[:r#
} D'Byl,W$
} Uk|Xs~@#E
d?b2jZ$r]
)l[ +7
public void splitterStop() UbY-)9==
{ JY9Hqf
bStop = true; j#-ZL-N
} T=;'"S
N+HN~'8r
<^n9?[m*
} \&@Tq-o
#^!oP$>1
RX?Nv4-
/* *|_u~v:)|5
**FileAccess.java 9e=F
*//文件访问(定位，写) $qg5m,1?
package NetFox; Gp;[WY\
import java.io.*; il5WLi;{
3_^w/-7`B
:Gy .P
public class FileAccessI implements Serializable{ ;Jv)J3y
lG fO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =!{}:An1$
RandomAccessFile oSavedFile; UupQ*,dJ
long nPos; )c]GgPH
+Nc|cj
?P{C=Td2z
public FileAccessI() throws IOException N5%~~JRO
{ EJdq"6S
this("",0); 3"I1'+
} *7BY$q
Q}\,7l
7 &GhJ^Ku
public FileAccessI(String sName,long nPos) throws IOException pfZn<n5p
{ 6S"bW)O
oSavedFile = new RandomAccessFile(sName,"rw"); =*"Amd,
this.nPos = nPos; uW Q`
oSavedFile.seek(nPos); wqA5GK>m2
} )ckx&e
5!tmG- 'b
N4)&K[
public synchronized int write(byte[] b,int nStart,int nLen) YA{Kgc^
{ [OH>NpL
int n = -1; {\C$Bz
try{ /YUf('b
oSavedFile.write(b,nStart,nLen); x9-K}s]%
n = nLen; wnt^WW=a[
} ]y.,J
catch(IOException e) EU>@k{Qt
{ -_>c P
e.printStackTrace (); 8ru@ 8|r
} w>/KQ> \"
>[ lj8n
j1**Ch/
return n; *Vv ;NA/
} 1;.}u=8
4zJ9bF4
"/ @ ;6
} KC q3S
(873:"(
IK~ur\3
/* D!qtb6<.
**SiteInfoBean.java n$#^gzU4
*/ % fA0XRM
package NetFox; HAGWA2wQ
bcz<t)
O!Mm~@MoA
public class SiteInfoBean { xv4nYm9
z)QyQ
)TRDM[u
private String sSiteURL; //Site's URL E%H,Hk^
private String sFilePath; //Saved File's Path g6 7*Bs
private String sFileName; //Saved File's Name 'Nfg%)-N
private int nSplitter; //Count of Splited Downloading File NmOQ7T
I0Wn?Qq=@
Haq23K
public SiteInfoBean() eUF PzioW
{//nSplitter的缺省值为5 IQ2<Pinv
//default value of nSplitter is 5 ELY$ ]^T
this("","","",5); JK,#dA#
} ,ZMYCl]
yU .B(|
~@itZ,d\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -#rFCfPy^
{ tH>%`:
sSiteURL= sURL; 1(On.Y=
sFilePath = sPath; ~)oC+H@{
sFileName = sName; 6JK;]Ah
this.nSplitter = nSpiltter; =YLt?5|e
4~Lw:o1a
sI*( MhU
} G@,qO#5&
Lc<Gny^
F!zZIaB]
public String getSSiteURL() ,aawtdt/
{ Ix1ec^?f
return sSiteURL; Zh3]bg5
} 3bE^[V8/
}c&Zv#iO6
$5il]D`
public void setSSiteURL(String value) }"q1B
{ 0qR;Z{k
sSiteURL = value; H~x0-q<8
} I>9rfmmTI
]Ms~;MXlx5
;=B&t@
public String getSFilePath() v6oZD;;~
{ Dk]Y\:
return sFilePath; -#)xeW.d
} p9l&K/
n-H0cm
H3`%#wQ0j
public void setSFilePath(String value) L6l~!bEc
{ m#%5H
sFilePath = value; ]!0*k#i_.
} cC4*4bMm
;h
I"<~!krt%
public String getSFileName() T(ponLh
{ |mmIu_
return sFileName; ?P"ht
} m;Sw`nw?
-R6z/P(}
?*}V>h 8m)
public void setSFileName(String value) Z(Q?epyT
{ p?Yovckm
sFileName = value; o^DiIoor
} ]IyC
!t;$n!7<
3ck;~Ncj<
public int getNSplitter() ?bN8h)>QQ8
{ 173/A=]
return nSplitter; Q v{q:=k
} siyJjE)}w
RJBNY;0
C(W?)6?
public void setNSplitter(int nCount) w="I*7c@
{ n"_EDb
nSplitter = nCount; M%9PVePOe
} k}jH
} ~rn82an@G
&a48DCZ
rBgLj,/`U/
/* wPqIy}-
**Utility.java Qj0@^LA
*/ r,yhc =
package NetFox; |? r,W~9`
].:S!QO
(M5=8g%>d
public class Utility { NSM-p.I9
V=E9*$b]
yt_?4Hc"
public Utility() o{zo-:>Jp
{ p|AIz3
S'TF7u
NGS/lKz
} %)q5hB
CE*@CkC0z
//线程睡眠 M^g"U`
public static void sleep(int nSecond) ]u2!)vZh'
{ (A(d]l
try{ G4<'G c
Thread.sleep(nSecond); ;QgJw2G
} =b9?r
catch(Exception e) npbNUKdz
{ na8A}\!<
e.printStackTrace (); \>9%=32u.
} WnHf)(J`"
} `wk#5[Y_
fdp/cwd
//日志 >cSc
public static void log(String sMsg) Dc BTW+
{ PiAA,
System.err.println(sMsg); p^~lQ8t
} ? )0U!)tK
*,pG4kh!
X}Fc0Oo
public static void log(int sMsg) tlvLbP*r
{ r6MQ|@
System.err.println(sMsg); M@{GT/`Pf
} X "1q$xwc
} }$iH3#E8
n*bbmG1
KvktC|~?
/* GH^i,88
**TestMethod.java PTL52+}/
*/ PtmdUHvD
package NetFox; }bix+/]
FV:{lC{h~
HOu<,9?>Q
public class TestMethod { j:]/AReOL
_=4Dh/Dv
yfuvU2nVH
public TestMethod() y;#p=,r
{ ///xx/weblogic60b2_win.exe l+YpRx/T\
try{ 7nIg3s%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #sNa}292"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i"|'p/9@q
SiteFileFetch fileFetch = new SiteFileFetch(bean); )t@OHSl
fileFetch.start(); k)y0V:ZY]O
} MLa]s* ; d
catch(Exception e){e.printStackTrace ();} BflF*-s ^
bQ
(:E^} &A
} Jq?ai8
##R]$-<4dQ
C{Aeud #5
public static void main(String[] args) y>Nlj%XH
{ .KRh59yg
new TestMethod(); D~2,0K
} ?]$.3azO
} jd(=? !_
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