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)); 1(R}tRR7R
} f~R(D0@
for(int i=0;i<nEndPos.length-1;i++) ECuH%b^,
{ %)1?TU
nEndPos = nStartPos[i+1]; Gj?t_Zln
} exUFS5d
nEndPos[nEndPos.length-1] = nFileLength; .!3|&V'<
} P3=G1=47U
} Bm<`n;m
ltSU fI
+@f26O7$*
//启动子线程 lfgq=8d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /Cr%{'Pzk
for(int i=0;i<nStartPos.length;i++) ;ef}}K
{ o:'MpKm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GL}]y -f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ec;o\erPG
nStartPos,nEndPos,i); I$G['`XX/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {dlXLx!B
fileSplitterFetch.start(); ^uc=f2=>,
} z&\a:fJ&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iWkWR"ysy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |YWD8 +
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", adcE'fA<_
nEndPos = " + nFileLength); [|$h*YK
// fileSplitterFetch[nPos.length-1].start(); {S)6;|ua'
O=t_yy
Ll't>)
//等待子线程结束 YkSl^j[DHs
//int count = 0; +Kc
//是否结束while循环 &r/Mi%
boolean breakWhile = false; $%d*@'c
T?0eVvM
BDDlQci38
while(!bStop) O0v}43J[
{ F/{!tx
write_nPos(); T'9'G M
Utility.sleep(500); Sz`,X0a
breakWhile = true; t3_O H^
;[DU%f
zC!t;*8a
for(int i=0;i<nStartPos.length;i++) $h"\N$iSq
{ 9cF[seE"0
if(!fileSplitterFetch.bDownOver) 8TKnL\aar
{ >tr}|>
breakWhile = false; cuITY^6
break; _TZRVa_
} tcI*a>
} (?c"$|^J
if(breakWhile) Rhs/3O8k
break; 7n<{tM
UI0VtR]
j,eo2HaL
//count++; Zu[su>\
//if(count>4) q]-r@yF
// siteStop(); b8UO,fY q
} #c!lS<z
Ld~/u]K%V
C&%_a~
System.err.println("文件下载结束！"); {VRf0c
} CHX#^0m.
catch(Exception e){e.printStackTrace ();} Wac&b
} 0{D'n@veP
va@Lz&sAE%
J ZS:MFA
//获得文件长度 r#a=@
public long getFileSize() oG\Vxg*
{ 2[W&s&
int nFileLength = -1; a;+9mDXx:
try{ 8nV+e~-w
URL url = new URL(siteInfoBean.getSSiteURL()); +r2-S~f3N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CA~-rv
httpConnection.setRequestProperty("User-Agent","NetFox"); ?6U0PChy
{EQOP]
g) jYFfGfH
int responseCode=httpConnection.getResponseCode(); ~$^XP.a.
if(responseCode>=400) }Sv:`9=
{ Y$_B1_
processErrorCode(responseCode); #\OA)`U
return -2; //-2 represent access is error ~f98#43
} usF.bkTp
8l`*]1.W<
#*Ctwl,T
String sHeader; 3s#N2X;Bc
y<Ot)fa$
~c `l@:
for(int i=1;;i++) 57c8xk[.2
{ UCjld
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g($2Dk_F2
//Utility.log(in.readLine()); NBGH_6DROw
sHeader=httpConnection.getHeaderFieldKey(i); e\L8oOk#r
if(sHeader!=null) YOO+R{4(
{ ?e 4/p
if(sHeader.equals("Content-Length")) 5\nAeP
{ F)eelPZ+,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \4fQMG
break; c^W)07-X5y
} rey!{3U
} =aW9L)8D
else Dlvz)
break; +I28|*K"
} \9T7A&
} K$=zi}J W
catch(IOException e){e.printStackTrace ();} 6'f;-2
catch(Exception e){e.printStackTrace ();} ckCE1e>s
D0f]$
J|73.&B
Utility.log(nFileLength); `ERz\`d~Y;
&};zvo~P.
+NUG
return nFileLength; nxFBID
} eHUOU>&P]
kAUymds;O
ef4 i:.
//保存下载信息（文件指针位置） ~P-mC@C
private void write_nPos() CrTw@AW9)
{ 4Z0]oIX
try{ G3T]`Atf
output = new DataOutputStream(new FileOutputStream(tmpFile)); /)O"l@ }U
output.writeInt(nStartPos.length); ~k5W@`"W
for(int i=0;i<nStartPos.length;i++) JxU5 fe
{ Q7CsJzk~)
// output.writeLong(nPos); [$UI8tV
output.writeLong(fileSplitterFetch.nStartPos); t]G:L}AOl
output.writeLong(fileSplitterFetch.nEndPos); X:{!n({r=
} @H8EWTZ
output.close(); seJ^s@H5l
} {'H(g[k
catch(IOException e){e.printStackTrace ();} \ Cj7k^
catch(Exception e){e.printStackTrace ();} f|gg
} Y'X%Aw;`
HGg@ _9tW
)4;`^]F
//读取保存的下载信息（文件指针位置） BiBOr}ZQ
private void read_nPos() 9Mcae31
{ _yR^*}xJb
try{ e*1_8I#2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R4d=S4i
int nCount = input.readInt(); a 1*p*dM#
nStartPos = new long[nCount]; uB?ZcF}Tk
nEndPos = new long[nCount]; "0TZTa1e
for(int i=0;i<nStartPos.length;i++) )V9bI(v
{ lp8v0e4
nStartPos = input.readLong(); dj%!I:Q>u
nEndPos = input.readLong(); W2!+z{:m
} A3*!"3nU
input.close(); X@FN|Rdh
} qqU 64E
catch(IOException e){e.printStackTrace ();} hi[pVk~B)
catch(Exception e){e.printStackTrace ();} 5!9zI+S|=`
} Flb&B1
],].zlN
\'j|BJ~L f
private void processErrorCode(int nErrorCode) %&bY]w
{ ,hmL/K0"(5
System.err.println("Error Code : " + nErrorCode); *X}`PF
} sDV Q#}a
OZ;*JR:
=2x^nW
//停止文件下载 w4Z'K&d=
public void siteStop() f%hEnZv
{ poFg1
bStop = true; ybUaTD@?}b
for(int i=0;i<nStartPos.length;i++) 4B][S'f
fileSplitterFetch.splitterStop(); > Nr#O
#X"@<l4F
akQ7K
} Oow2>F%_#
} BDVtSs<7
//负责部分文件的抓取 8dhUBJ0_
**FileSplitterFetch.java =vhm}
*/ <a+Z;>
package NetFox; QmIBaMI#
a'IdYW0
? =+WRjF
import java.io.*; tLmTjX .6
import java.net.*; teVM*-
4KrL{Z+}
T6k0>[3xf
public class FileSplitterFetch extends Thread { 3+bt~J0
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t#"Grk8Mz&
String sURL; //File URL rVsJ`+L
long nStartPos; //File Snippet Start Position <54 S
long nEndPos; //File Snippet End Position Y6d@h? ht
int nThreadID; //Thread's ID vr^qWn
boolean bDownOver = false; //Downing is over ,Y48[_ymm
boolean bStop = false; //Stop identical Du){rVY^d
FileAccessI fileAccessI = null; //File Access interface Lj;2\]
<0?W{3NqI
PFK '$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WuW^GC{7
{ g=o4Q< #^y
this.sURL = sURL; Yz<1 wt7;
this.nStartPos = nStart; @s^-.z
this.nEndPos = nEnd; RpYERAgT
nThreadID = id; o _H`o&xr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )\^-2[;
} $,'*f?d
\uMLY<]P
N}YkMJy
public void run() ~e.L.,4QZ8
{ gPc=2
while(nStartPos < nEndPos && !bStop) t&DEb_"De
{ Ti&z1_u
29q _BR *:
`@|$,2[C
try{ ^sg,\zD 'X
URL url = new URL(sURL); C"enpc_C/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3oG,E;(
httpConnection.setRequestProperty("User-Agent","NetFox"); >yh2Lri
String sProperty = "bytes="+nStartPos+"-"; tklH@'q
httpConnection.setRequestProperty("RANGE",sProperty); \D&KC,i5f
Utility.log(sProperty); /H+a0`/
C{wEzM:
M& CqSd
InputStream input = httpConnection.getInputStream(); \5cpFj5%
//logResponseHead(httpConnection); }4S6Xe
;6hOx(>`=
2)~> R
byte[] b = new byte[1024]; 1@=po)Hnp
int nRead; '[O;zJN;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uRe'%?W
{ da~],MN
nStartPos += fileAccessI.write(b,0,nRead); &G$Ucc `
//if(nThreadID == 1) KCDE{za
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P L+sR3bR
} s&J]zb`
R_xRp&5
.w,q0<}
Utility.log("Thread " + nThreadID + " is over!"); HE_8(Ms;8
bDownOver = true; Vs{|xG7WD
//nPos = fileAccessI.write (b,0,nRead); 5ms(Wd
} G9vpt M
catch(Exception e){e.printStackTrace ();} G9@0@2aY8
} @AuO`I@p=
} ?b5^
<_KIK
Nl(Foya%)
//打印回应的头信息 VOh4#%Vj
public void logResponseHead(HttpURLConnection con) @$K"o7+]
{ F1Bq$*'N$w
for(int i=1;;i++) ,3 u}x,
{ {2"zVt#h
String header=con.getHeaderFieldKey(i); ~.lPEA %%
if(header!=null) jm r"D>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Mh 7DV
Utility.log(header+" : "+con.getHeaderField(header)); {T~#?v(
else -RK- Fu<e
break; k+l b@!
} 9k[9P;"F:
} 8qu6.
n@[O|?S
%GIr&V4|
public void splitterStop() F^fdIZx
{ 2T[9f;jM'
bStop = true; $a ` G
} <yg F(
&XUiKnNW
tIS<U(N;
} QnX(V[
*EwR!L*
0S$N05
/* =zs`#-^8
**FileAccess.java t9IW/Q
*//文件访问(定位，写) 57'4ljvYi
package NetFox; U_c*6CK
import java.io.*; gr-OHeid
@49S`
Hl |z</*+
public class FileAccessI implements Serializable{ 3%=~)7cF
zT?D<XW>1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DrK{}uM
RandomAccessFile oSavedFile; y Fq&8 x<X
long nPos; ;@E$}*3[>V
LvYB7<zk>
m/EFHS49
public FileAccessI() throws IOException 4#hSJ(~7S
{ cDkf qcC
this("",0); dzrio-QU~
} 4x[S\,20
!brf(-sr)
ZO$%[ftb
public FileAccessI(String sName,long nPos) throws IOException [Cv/{f3]u{
{ I?G:p+
oSavedFile = new RandomAccessFile(sName,"rw"); r1RM
this.nPos = nPos; 5bpEYW+
oSavedFile.seek(nPos); R<N ]B
} |*tp16+6
}txX;"/
Aj]V`B:65
public synchronized int write(byte[] b,int nStart,int nLen) FH+s s!
{ \v)+.m?n
int n = -1; gCY';\f!
try{ v0jgki4t
oSavedFile.write(b,nStart,nLen); [QT#Yf0
n = nLen; TBU&6M>{3
} I`4*+a'q&
catch(IOException e) L4y4RG/SJ:
{ y9}>:pj4
e.printStackTrace (); $l&(%\pp
} 8 uwq-/$
n^6j9FQ7
N^:9Fz
return n; %&t<K3&Yh
} ,7K`[
(qulwOt~w
sYf~c0${
} O]1(FWYy
tT?cBg{
vn"{I&L+w0
/* !ff&W1@
**SiteInfoBean.java $(>+VH`l
*/ R`^_(yn>
package NetFox; hSyql
#],&>n7'
F6flIG&h
public class SiteInfoBean { i5,kd~%O
y>e.~5;
_[ZO p ~
private String sSiteURL; //Site's URL < F+l
private String sFilePath; //Saved File's Path C/6V9;U
private String sFileName; //Saved File's Name :'*~uJrR
private int nSplitter; //Count of Splited Downloading File D]Xsvv #
55c|O
q;>7*Y&
public SiteInfoBean() (+y
{//nSplitter的缺省值为5 .z}~4BY
//default value of nSplitter is 5 K~ehP[^
this("","","",5); P;]F(in=
} `(/w y
AoL2@C.C%D
Ng>h"H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) dQR-H7U
{ Qhcu>ra
sSiteURL= sURL; ?]Xpi3k
sFilePath = sPath; qVwIo.g!
sFileName = sName; =xx]@
this.nSplitter = nSpiltter; 'qX|jtdM
..'_o~Ka
#d2.\X}A"3
} z]D69O b
FZE"7ec>m
Bad:no\W
public String getSSiteURL() JQHvz9Yg
{ tc{sB\&-
return sSiteURL; !6Mo]xh
} O2dW6bt
)*x6 FfTUd
u-G+ j)
public void setSSiteURL(String value) Jd^,]
{ GKc`xIQ
sSiteURL = value; Qtv&ijFC
} i5?q,_
R>mmoG}MQ[
I->Ss},U
public String getSFilePath() qfRH5)k
{ 5 -RsnF
return sFilePath; 6h,(wo3Y
} (7=!+'T"
74k dsgQf
s 3f-7f<
public void setSFilePath(String value) O]Qd<%V'x
{ 3Xy-r=N.l
sFilePath = value; en*GM}<V
} G`BU=Fi
0eu$ W
3r."j2$Hs0
public String getSFileName() zz4N5["
{ ktBj|-'>
return sFileName; _k~KZ;l
} [o+q>|q
y0.8A-2:
.Cl:eu,]
public void setSFileName(String value) c*L\_Vx+
{ iq( E'`d
sFileName = value; EkNunCls
} @? QoF#D
QD*35Y!d
[dIXR
public int getNSplitter() WE.{p>
{ ll.N^y;a
return nSplitter; p(`6hWx
} ~T,c"t2
Xe:jAkDp
yS(fILV
public void setNSplitter(int nCount) 8sM|%<$=j
{ EL 8<U
nSplitter = nCount; RA'M8:$
} sjwo/+2
} 5aZ2j26
Xi,CV[L\
^c4@(]v'G
/* g<f <Ip=
**Utility.java N&g3t%F
*/ nR}sNl1
package NetFox; 5l2 ?
7gvnl~C(
92x(u%~E
public class Utility { 6NM:DI\%
!y:vLB#q
RcM/!,B
public Utility() 2Mvrey)
{ :f}9($
,<tX%n`v=
T;y>>_,
} >dG;w6y'
b TM{l.Aq3
//线程睡眠 %GA"GYL9'
public static void sleep(int nSecond) evAMJ=
{ ,3p~w5C/+[
try{ BJsz2t :0
Thread.sleep(nSecond); #W'HR
} > BY&,4r
catch(Exception e) XJ` ]ga
{ Z/0fXn})
e.printStackTrace (); (SDr!!V<
} {/(D$"j(S
} 7- ] as$
bM!_e3ik;
//日志 G{ sOR
public static void log(String sMsg) ^*8G8'k;$
{ m)v"3ib
System.err.println(sMsg); `V]5sE]G
} bE#,=OI$
zHL@i0>^
ICs\ z
public static void log(int sMsg) PQnF
{ !^=*Jq>
System.err.println(sMsg); 6[LM_eP
} vCxD~+zf
} D2!X?"[P
UAFwi%@!-q
Xti[[sJ
/* O[s{ Gk'>
**TestMethod.java ;"fDUY|
*/ eg?<mKrZ
package NetFox; !QHFg-=7
9XyYHi
FsV'Cu@!U
public class TestMethod { 8U>B~9:JO
L[H5NUG!
EB=-H#
public TestMethod() jN>{'TqW4
{ ///xx/weblogic60b2_win.exe !*m5F8Qm?A
try{ LuSLkLN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %Bn?n{/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V|/NB
SiteFileFetch fileFetch = new SiteFileFetch(bean); ') gi%
fileFetch.start(); :xD=`ib
} v!Pb`LCqK
catch(Exception e){e.printStackTrace ();} Nq` C.&
P8>d6;o($
xA1hfe.9
} `m>*d!h=
RGg(%.
B}?5]N==]
public static void main(String[] args) C>$E%=h+_
{ ~ ! 3I2
new TestMethod(); " '6;/N
} qT"Q1xU[
} Bck7\
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