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)); t=Jm|wJnUA
} V'j@K!)~xR
for(int i=0;i<nEndPos.length-1;i++) alc]
{ vu<#wW*9
nEndPos = nStartPos[i+1]; a&C.=
} zFywC-my@
nEndPos[nEndPos.length-1] = nFileLength; .9OFryo
} 3?@?-q2g
} IO"hF
Y87XLvig}
0vn[a,W<A
//启动子线程 0aogBg_@K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &L%Jy #=
for(int i=0;i<nStartPos.length;i++) Ib6(Bp9.L
{ Pxqiv9D<R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -TTs.O8P|<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {OCJ(^8i
nStartPos,nEndPos,i); Yy hny[fa9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =T4u":#N;
fileSplitterFetch.start(); 'B`#:tX^N
} g8l5.Mpx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v,jhE9_O0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x,\!DLq:p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !R6ApB4ZI
nEndPos = " + nFileLength); 3$_*N(e
// fileSplitterFetch[nPos.length-1].start(); *T1~)z}j<
jgq{pZ#E
Bc<n2 C0
//等待子线程结束 @VK6JjIq
//int count = 0; ('4wXD]C
//是否结束while循环 .,M;huRg
boolean breakWhile = false; TBnvV 5_
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while(!bStop) ,{8v4b-
{ Kt6>L5:94
write_nPos(); Ly>OLI0x_
Utility.sleep(500); `Mk4sKU\a
breakWhile = true; 1 i3k
="'- &
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for(int i=0;i<nStartPos.length;i++) k>5O`Y:
{ 8+&JQ"UaB
if(!fileSplitterFetch.bDownOver) kjE*9bUc
{ L/i(KF{
breakWhile = false; 6P*O&1hv
break; J(s;$PG
} %K1")s
} ]JMl|e
if(breakWhile) FN?3XNp.
break; HnU Et/
au$"B/
OCK>%o$[
//count++; P^i.La,
//if(count>4) H;S%Y`V
// siteStop(); Cj^{9'0
} hO( RZ'{
X+l'bp]Ry
;`UecLb#
System.err.println("文件下载结束！"); SaO3zz@L
} x_!ZycEa
catch(Exception e){e.printStackTrace ();} kg>>D
} ^E,1V5
CDdkoajBa
f$F*3
//获得文件长度 M_|> kp
public long getFileSize() \#6Fm_b]u
{ +iA=y=;blH
int nFileLength = -1; RiR:69xwR*
try{ \ZH&LPAY
URL url = new URL(siteInfoBean.getSSiteURL()); b{5K2k&,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =SBBvnPLI
httpConnection.setRequestProperty("User-Agent","NetFox"); yI)~]K r
>NM\TLET~
LFu%v7L`
int responseCode=httpConnection.getResponseCode(); ax|1b`XUr"
if(responseCode>=400) UtJa3ya
{ #YK5WTn5
processErrorCode(responseCode); rU2iy"L
return -2; //-2 represent access is error SEd5)0X^
} yL1CZ_
I%lE;'x
z`U Ukl}T
String sHeader; R_kQPP
thW<
^b-18 ~s
for(int i=1;;i++) `<fh+*
{ }!s!;BOx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); glUo7^ay7
//Utility.log(in.readLine()); n(vDytrj;
sHeader=httpConnection.getHeaderFieldKey(i); ]axh*J3`i
if(sHeader!=null) JPx7EEkZR4
{ 80B>L
if(sHeader.equals("Content-Length")) Fn|gVR
{ ?mYYt]R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'Kbl3fUF
break; - u3e5gW
} 0l\y.
} 3,eIB(
else AuiFbRFi
break; pa<qZZ
} -J0WUN$2*
} 7;}l\VXHm
catch(IOException e){e.printStackTrace ();} oC|WBS
catch(Exception e){e.printStackTrace ();} `a]44es9q
l!~ mxUb
Ufid%T'
Utility.log(nFileLength); :@3Wg3N
my.`k'
e}{U7xQm1
return nFileLength; }_OM$nzj
} 6][1<}8
^U q
wts:65~
//保存下载信息（文件指针位置） O8u3y
private void write_nPos() k|E]YvnfG
{ `,>wC+}
try{ PX,rWkOce
output = new DataOutputStream(new FileOutputStream(tmpFile)); -X1X)0v$
output.writeInt(nStartPos.length); %{5n1w
for(int i=0;i<nStartPos.length;i++) 2WBq
{ 3I=kr
// output.writeLong(nPos); -uR72f
output.writeLong(fileSplitterFetch.nStartPos); "^CXY3v
output.writeLong(fileSplitterFetch.nEndPos); )Hw:E71h2
} {rH9grb
output.close(); u5E]t9~Pq
} JBX[bx52<r
catch(IOException e){e.printStackTrace ();} m7|RD]q&
catch(Exception e){e.printStackTrace ();} w!3>N"em
} ]<w:V`(
pa]"iZz
=tdSq"jh
//读取保存的下载信息（文件指针位置） `$RA< 3
private void read_nPos() 3{Q,hpZN
{ Y:QD
try{ +5p{5 q(o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6vy7l(%
int nCount = input.readInt(); 1(dj[3Mt
nStartPos = new long[nCount]; %@J1]E;
nEndPos = new long[nCount]; m6n!rRQ^U
for(int i=0;i<nStartPos.length;i++) X]*QUV]i
{ &*,:1=p
nStartPos = input.readLong(); woOy*)@
nEndPos = input.readLong(); x^=M6;:
} 9}tG\0tL*
input.close(); Q=cQLf;/'
} $&P?l=UG
catch(IOException e){e.printStackTrace ();} MBr:?PE7
catch(Exception e){e.printStackTrace ();} {bNXedZ\
} 4&^9Wklj
QBJ3iQs1
7S^""*Q^
private void processErrorCode(int nErrorCode) =!MY4&YX
{ t!;/Z6\Pb
System.err.println("Error Code : " + nErrorCode); [w\?j,
} dKhA$f~
YE+$H%Jl!
Xh+ia#K
//停止文件下载 deX5yrvOie
public void siteStop() ?(zoTxD
{ 3TuC+'`G
bStop = true; /\d$/~BFi
for(int i=0;i<nStartPos.length;i++) f^Bc
fileSplitterFetch.splitterStop(); LJzH"K[Gg6
Q[ieaL6&
I*[tMzE
} H^%.=kf
} mryN}
//负责部分文件的抓取 &~sfYW
**FileSplitterFetch.java q" @
*/ tJI,r_
package NetFox; jdqj=Yc
<&!]K?Q9i
-#&kYK#Ph
import java.io.*; ni CE\B~
import java.net.*; *gsAn<
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(X[2TT3j!
public class FileSplitterFetch extends Thread { D vkxI<Xa
mXWTm%'[
Fw4*
String sURL; //File URL ,\PVC@xJ
long nStartPos; //File Snippet Start Position 'md0]R|
long nEndPos; //File Snippet End Position -C7FuD[Xw
int nThreadID; //Thread's ID uYO|5a<f~
boolean bDownOver = false; //Downing is over JQKdW
boolean bStop = false; //Stop identical zzpZ19"`1
FileAccessI fileAccessI = null; //File Access interface Xo5$X7m
qB6dFl\ (
cSP*f0n,eo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "&YYO#YO
{ i^Ut015q%
this.sURL = sURL; m7]hJ,0
this.nStartPos = nStart; *e.*=$
this.nEndPos = nEnd; / l>.mK()
nThreadID = id; DtCEm(b0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MEZ{j%-a
} ~fN%WZ;_
| FM }
*U7%|wd
public void run() nn~YK
{ FVWfDQ$&v
while(nStartPos < nEndPos && !bStop) $r.U
{ Xh3;
"l~Ci7& !a
t={0(
try{ dJ3IUe
URL url = new URL(sURL); hXL|22>w<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O_,O,1
httpConnection.setRequestProperty("User-Agent","NetFox"); ;6;H*Y0,|E
String sProperty = "bytes="+nStartPos+"-"; z5cYyx r>
httpConnection.setRequestProperty("RANGE",sProperty); n~0z_;5
Utility.log(sProperty); Ggm` ~fS
0~A#>R'
W.}].7}h
InputStream input = httpConnection.getInputStream(); %|Qw9sbd
//logResponseHead(httpConnection); BNm4k7 ]M
5>0.NiXGf'
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byte[] b = new byte[1024]; M].8HwC+
int nRead; Zc5 :]]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dDcZ!rRaL@
{ E)p9eU[#
nStartPos += fileAccessI.write(b,0,nRead); '&yg{n
//if(nThreadID == 1) m\0cE1fir
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :R6Q=g=
} wrv5V M}
2Oc$+St~8
?m%h`<wgMc
Utility.log("Thread " + nThreadID + " is over!"); Lubrn"128
bDownOver = true; $~u.Wq
//nPos = fileAccessI.write (b,0,nRead); 4jwu'7Q
} 649 !=
catch(Exception e){e.printStackTrace ();} `iixq9xi
} F@W*\3)
} ,Qc.;4s-
Epjff@7A
zmFws-+A
//打印回应的头信息 mV\$q@sII
public void logResponseHead(HttpURLConnection con) r|Zi3+
{ 5G*II_j
for(int i=1;;i++) C8b''9t.
{ c[(Pg%
String header=con.getHeaderFieldKey(i); :{}_|]>K
if(header!=null) BSUPS+@+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XAic9SNu;
Utility.log(header+" : "+con.getHeaderField(header)); BWK IbG
else 7>.OVh<
break; F8mC?fbK9
} KCqqJ}G
} 8I#D`yVKc
iD_TP
i57( $1.
public void splitterStop() ;iX<`re~
{ W kkxU.xXE
bStop = true; ,)#.a%EKA
} otriif@+Z
x-Z^Q C
C3"&sdLb$
} R}%8s*
v*TeTA %
J_"3UZ~&
/* P[i\e7mR
**FileAccess.java sBjXE>_#)
*//文件访问(定位，写) 8&(-8
package NetFox; >4)g4~'n!
import java.io.*; "'{OIP
iJnh$jo
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public class FileAccessI implements Serializable{ uWc:jP
"iek,Y}j7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ntHT
RandomAccessFile oSavedFile; "$@,n7k
long nPos; *{[d%B<lp
LknVqZ|k
g!^J,e=
public FileAccessI() throws IOException >d%VDjk .
{ FAtWsk*pgY
this("",0); P(_(w 9
} pt})JMm
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public FileAccessI(String sName,long nPos) throws IOException Xp^$ E6YFy
{ Bbs 0v6&,
oSavedFile = new RandomAccessFile(sName,"rw"); H m8y]>$
this.nPos = nPos; 7A0dl}:
oSavedFile.seek(nPos); ZNy9_a:dX
} ,%8$D-4#_
|[WL2<
ha>SZnKD{
public synchronized int write(byte[] b,int nStart,int nLen) 8p,>y(o
{ qw0~*0}
int n = -1; =ZMF]|
try{ %8<2>
oSavedFile.write(b,nStart,nLen); n)CH^WHL&
n = nLen; dqz1xQ1
} 6o(lObfo
catch(IOException e) }K;iJ~kD1
{ Nh:4ys!P
e.printStackTrace (); Nuq(4Yf1W
} s((b"{fFb
hU+#S(t>b
`skH-lk,
return n; @?M;'xMbB
} ir+8:./6
Xv&%2-V;
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} w= B
8E-Ip>{>
Vy r] x
/* ku-cn2M/
**SiteInfoBean.java Crg#6k1~EN
*/ -G!6U2*#
package NetFox; 9JXhHAxD
Tz2x9b\82
(I!1sE!?1
public class SiteInfoBean { 9<w=),R`8
9?!u2 o
W n6,U=$3
private String sSiteURL; //Site's URL DbQBVy
private String sFilePath; //Saved File's Path uzO{{S-
private String sFileName; //Saved File's Name 4a1BGNI%SW
private int nSplitter; //Count of Splited Downloading File KG-UW
Qw}xGlF,
g\qX7nIH?
public SiteInfoBean() ym[+Rw
{//nSplitter的缺省值为5 C~:b*X
//default value of nSplitter is 5 <G&WYk%u*
this("","","",5); Jfe~ ,cI
} L2k;f]
Qk|( EFQ9
@H3|u`6V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2-p8rGI_F
{ }@3$)L%n_u
sSiteURL= sURL; F61+n!%8
sFilePath = sPath; xL|?(pQ/BK
sFileName = sName; ADTU{6UPS
this.nSplitter = nSpiltter; *P&OxVz
|%n|[LP'
N4' .a=1
} LxIuxt=X|p
B>1M$3`E
Mp!2`4rD
public String getSSiteURL() W5TqC
{ {E3;r7
return sSiteURL; 4 3}qaf[
} kVy"+ZebK
(69kvA&|q
_P>1`IR
public void setSSiteURL(String value) 6ch@Be5*
{ KwY`<t1lA;
sSiteURL = value; A[K:/tB
} no eb f
*4zoAslU1
3L%Y"4(mm
public String getSFilePath() R65;oJh
{ r7zf+a]
return sFilePath; cKaL K#~
} ER0TY,
Z#H@BWN7
Rh5@[cg%
public void setSFilePath(String value) #1gTpb+t
{ aMe%#cLI
sFilePath = value; OFJJ-4[_3
} 0]f?Dx/8
6,sRavs
DK2c]i^|=
public String getSFileName() GA({ri
{ '5&B~ 1&
return sFileName; qdg= Imx
} cj,&&3sbV
hg)!m\g
1"87EP
public void setSFileName(String value) ?)i6:76(
{ 1aXIhk4
sFileName = value; #$9U=^Z[
} D| 3AjzW
^v()iF !
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public int getNSplitter() CJ37:w{%*Y
{ + xkMW%e<
return nSplitter; 6PVlZ
} #CBo
]kU~#WT
_A# x&<c
public void setNSplitter(int nCount) "'LOaf$X
{ -0[>}!l=G
nSplitter = nCount; QZeb+r
} oQE_?">w
} #dXZA>b9
#oS
NWq [22X |
/* o>!~*b';g,
**Utility.java oWn_3gzw;
*/ \n('KVbf
package NetFox; 7i%P&oB
G+%5V5GS
TO8\4p*tE
public class Utility { \p_8YC
Q}`2Y^.
h_}BmJh_
public Utility() o7Z#,>`2
{ vFkyfX(
q,19NZ
U~QCN[gh
} %[31ZFYB
(*@~HF,t=
//线程睡眠 m/"=5*pA
public static void sleep(int nSecond) i(TDJ@}
{ N*c?Er@8U
try{ `dq3=
Thread.sleep(nSecond); pR^Y|NG!
} mqfEs0~I
catch(Exception e) Toa#>Z*+Rb
{ e&VR>VJEA
e.printStackTrace (); \q)1TTnHS
} &t@6qi`d
} R2Fh^x
L M<=j
//日志 r5$?4t
public static void log(String sMsg) [n@!=T
{ TW;;OS[
System.err.println(sMsg); GF,|;)ly
} @XSu?+s)
bm]dz;ljh
Jb-QP'$@
public static void log(int sMsg) xWI 0s;k
{ DcvmeGl
System.err.println(sMsg); R<YYf^y
} M5bj |tQ4
} %emPSBf@
ucm.~1G(
;ZW}47:BS6
/* q.K$b
**TestMethod.java i(qYyO'
*/ JV*,!5
package NetFox; uL{~(?U$
i1H80m s
?9ho|
public class TestMethod { d+| !6
*'S%gR=Aa+
_nCs$U
public TestMethod() g|*eN{g]uE
{ ///xx/weblogic60b2_win.exe +53zI|I
try{ X;a{JjN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4I[FE;^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >^)5N<t?
SiteFileFetch fileFetch = new SiteFileFetch(bean); vCe<-k
fileFetch.start(); UA u4x 7
} VX@G}3Ck
catch(Exception e){e.printStackTrace ();} Pw0KQUs
>+LgJo R
,$(v#Tz
} ] ,aAzjZ
D{d$L9.
>Ezwl5b
public static void main(String[] args) Xr6 !b:UX
{ U[ungvU1U
new TestMethod(); ?cxK~Y\
} }4ju2K
} "jJ)hk5e
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