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)); ;FuST
} (QojIdHt
for(int i=0;i<nEndPos.length-1;i++) 2^=.f?_YR
{ Ll%}nti
nEndPos = nStartPos[i+1]; 6uUzky
} .i )n1
nEndPos[nEndPos.length-1] = nFileLength; E:uTjXt
} yW*,Llb5
} !K2QD[x
Piw i
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//启动子线程 ml)\RL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #N|JC d_
for(int i=0;i<nStartPos.length;i++) ,y-!h@(
{ TtWzjt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o:*$G~. k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V@y&n1?6
nStartPos,nEndPos,i); (+xT5 2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jUZ$vyT
fileSplitterFetch.start(); X,lhVT |
} t+pA9^$[`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `WMU'ezF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NU'2QSU8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \R-'<kN.*
nEndPos = " + nFileLength); JSylQ201
// fileSplitterFetch[nPos.length-1].start(); {md5G$*%
U|QP]6v
q-@&n6PEOZ
//等待子线程结束 p Djt\R<f
//int count = 0; Gf+X<a
//是否结束while循环 9GT}_ ^fb
boolean breakWhile = false; Gr}NgyT<!D
B+jh|@-
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while(!bStop) B>I:KGkV
{ j,9/eZRZ
write_nPos(); I(k(p\l%
Utility.sleep(500); $tc1te
breakWhile = true; *5XOYb?'v.
xDPR^xY
"~zLG"
for(int i=0;i<nStartPos.length;i++) UxF9Ko( ]d
{ sV0NDM0
if(!fileSplitterFetch.bDownOver) $*:$-
{ w/PE)xA
breakWhile = false; Lr d-
break; II=!E
} VV54$a
} 9pr.`w
if(breakWhile) f)Y~F/[$P
break; :AQ9-&i/a-
0`v-pL0|
#Jp|Cb<qx
//count++; =w:)AWZ
//if(count>4) o9C#5%9
// siteStop(); +M#}(hK
} O:~J_Wwl!
MXDCOe~07
OZz!8-|wE
System.err.println("文件下载结束！"); H?ug-7k/
} YRv96|c,
catch(Exception e){e.printStackTrace ();} V[Sj+&e&
} +7AH|v8
XWNo)#_3
Akws I@@
//获得文件长度 k!bJ&} Q(b
public long getFileSize() -eD]gm
{ 8<ev5af
int nFileLength = -1; SXE@\Afj
try{ (c"!&&S^ =
URL url = new URL(siteInfoBean.getSSiteURL()); q \fyp\z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R>&8%%#
httpConnection.setRequestProperty("User-Agent","NetFox"); \P"Ol\@
*XYp~b
Z( "-7_
int responseCode=httpConnection.getResponseCode(); .LnknjC
if(responseCode>=400) mb%U~Na
{ =:6B`,~C
processErrorCode(responseCode); QoxQ"r9Wh
return -2; //-2 represent access is error ^K4?uABc
} yh|+Usa
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je3Qq1
String sHeader; ;R<V-gab
Bga4kjfmk
.wlKl[lE2
for(int i=1;;i++) \D]9:BNJ
{ x;/dSfv_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >Y+m54EE
//Utility.log(in.readLine()); Br{(sL0e
sHeader=httpConnection.getHeaderFieldKey(i); P*U^,Jh<
if(sHeader!=null) IGlyx'\_
{ ;i/? fw[h
if(sHeader.equals("Content-Length")) vCK+v r!
{ k{hNv|:,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BnDCK@+|Q
break; ^ZRZ0:rZ
} cW"DDm g
} zKaj<Og
else bC) <K/Q9
break; 0V^I.S/q
} Dbq/t^
} 2|WM?V&
catch(IOException e){e.printStackTrace ();} \I<R.49oW
catch(Exception e){e.printStackTrace ();} "Y4glomR[
pp7 $Q>6
[gZR}E
Utility.log(nFileLength); /;[x3}[
Q7d@+C
<%rm?;PBl
return nFileLength; s aHY9{)
} p&)d]oV>
kd]CV7(7
iC>%P&|-)|
//保存下载信息（文件指针位置） lkR^2P
private void write_nPos() Of$R+n.
{ TiG?r$6v%
try{ @de0)AJG6
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9HlWoHuC
output.writeInt(nStartPos.length); >El]5M7h7
for(int i=0;i<nStartPos.length;i++) 0 VG;z#{J
{ @0NWc c+
// output.writeLong(nPos); sX*L[3!vN
output.writeLong(fileSplitterFetch.nStartPos); 8|L@-F
output.writeLong(fileSplitterFetch.nEndPos); pjoyMHWK
} ,w9|?%S
output.close(); 2dHsM'ze
} Aho*E9VW
catch(IOException e){e.printStackTrace ();} \DBEs02
catch(Exception e){e.printStackTrace ();} L<B)BEE.
} WSv%Rxr8L
$;~YgOVZ5
F;kKn:XL
//读取保存的下载信息（文件指针位置） Br42Qo2"T>
private void read_nPos() Hi/[
{ V\e1NS
try{ 0S'@(p[A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sX3qrRY
int nCount = input.readInt(); L$+_
nStartPos = new long[nCount]; ZitmvcMk
nEndPos = new long[nCount]; o`7 Z<HF
for(int i=0;i<nStartPos.length;i++) ZH>i2|W<
{ =YfzB!ld
nStartPos = input.readLong(); Zs-lN*u7.
nEndPos = input.readLong(); ""|;5kJS4
} njO~^Hl7
input.close(); G!G:YVWXP
} o~L(;A]yN
catch(IOException e){e.printStackTrace ();} h+&iWb3;
catch(Exception e){e.printStackTrace ();} HVhd#Q;
} BSB&zp
mpVD;)?JmM
G`Z<a
private void processErrorCode(int nErrorCode) PlK3;
{ N`3^:EJL8
System.err.println("Error Code : " + nErrorCode); mO(Y>|mm
} so/0f1R?~
TA:uB[Ji
+{m+aHk
//停止文件下载 fE&s 6w&
public void siteStop() nt-_)4Fm
{ }aI>dHL
bStop = true; >H5t,FfQL
for(int i=0;i<nStartPos.length;i++) %6Vb1?x
fileSplitterFetch.splitterStop(); kzNRRs\e
jvD_{r
z 0zB&}
} i_l{#*t
} Gm9
//负责部分文件的抓取 (NDC9Lls
**FileSplitterFetch.java fkImX:|q
*/ I|>.&nb
package NetFox; a~LdcUYs
ST~YO
C&%NO;Ole
import java.io.*; o:"(\$
import java.net.*; 1[#sHj$Na`
J=(i0A
Bgzq
public class FileSplitterFetch extends Thread { kdx06'4o
.J&89I]U
S'w}Ir
String sURL; //File URL \/gf_R_GN
long nStartPos; //File Snippet Start Position 5K682+^5
long nEndPos; //File Snippet End Position @]8flb )T
int nThreadID; //Thread's ID BA@M>j6d
boolean bDownOver = false; //Downing is over b`j9}tZ
boolean bStop = false; //Stop identical T<b*=i
FileAccessI fileAccessI = null; //File Access interface /vi Ic %=
~Cw7.NA{3
A{k1MA<F6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \*qradgx$
{ NjA[(8\:
this.sURL = sURL; WS(m#WFQr
this.nStartPos = nStart; 0R`>F">
this.nEndPos = nEnd; G(Hr*T%
nThreadID = id; -"a(<JC^NI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S~ S>62
} "^BA5
ggkz fg&
?m7i7Dz
public void run() 2G!z/OAj
{ H"k$SPVS
while(nStartPos < nEndPos && !bStop) Nq$o{<1
{ `.3.n8V
ADB)-!$xoi
.f. tPm
try{ nN@ Ch
URL url = new URL(sURL); *8;<w~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <1m`
httpConnection.setRequestProperty("User-Agent","NetFox"); o"L8n(\
String sProperty = "bytes="+nStartPos+"-"; Eyk:pnKJb
httpConnection.setRequestProperty("RANGE",sProperty); eY^zs0
Utility.log(sProperty); -%P}LaC<
h8Oj E$ H
>SziRm>Y7
InputStream input = httpConnection.getInputStream(); 9=/4}!.
//logResponseHead(httpConnection); \Ucv<S
cXf/
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byte[] b = new byte[1024]; llh +r?
int nRead; u2$.EM/iae
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uTPAf^|
{ ydY 7 :D
nStartPos += fileAccessI.write(b,0,nRead); V=5*)i/
//if(nThreadID == 1) 7r)]9_[(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !O}e)t
} B B'qbX3xK
Ie=gI+2
K"5q387!
Utility.log("Thread " + nThreadID + " is over!"); 61&{I>~1
bDownOver = true; 7IkEud
//nPos = fileAccessI.write (b,0,nRead); ht>/7.p]
} x>BFK@#
catch(Exception e){e.printStackTrace ();} )b=vBs`%
} s6(md<r
} _/cX!/"
QlR~rFs9t
^-n^IR}J
//打印回应的头信息 ?[>Y@we
public void logResponseHead(HttpURLConnection con) +%KkzdS'
{ O{7#Xj :_
for(int i=1;;i++) f?eq-/UR
{ w2/3[VZ}l
String header=con.getHeaderFieldKey(i); )K$xu(/K
if(header!=null) hu"-dT;4]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YPq:z"`-y4
Utility.log(header+" : "+con.getHeaderField(header)); &(Hw:W9
else /-^J0f+l3
break; s"w^E\>6
} GE=S.P;
} u8|CeA
I?%q`GyP5
Qy4Pw\
public void splitterStop() !v9`oL26
{ $^czqA-&
bStop = true; wxj}k7_(`A
} QfPw50N;
L\c3D|
I5g|)Y Q
} 3="vOSJ6&
;!t?*
^J^FGo|M
/* G973n
**FileAccess.java *14:^neoI
*//文件访问(定位，写) #DJZ42
package NetFox; T<Qa`|5>
import java.io.*; v''J@F7
B~qo^ppVU
8f)pf$v`
public class FileAccessI implements Serializable{ fi~@J`
)t7MD(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 eX}aa0
RandomAccessFile oSavedFile; '/0e!x/8
long nPos; "zTy_0[;
L2}<2
7 H:y=?X6
public FileAccessI() throws IOException F]>+pU
{ 4@<wN \'
this("",0); xE!0p EHd
} 8@S]P0lk
O<,\tZ'N
@]2aPs} }6
public FileAccessI(String sName,long nPos) throws IOException 'o0o.&/=
{ yIngenr$
oSavedFile = new RandomAccessFile(sName,"rw"); zzo93d
this.nPos = nPos; 8<C@I/
oSavedFile.seek(nPos); $9X?LGUz
} vJVh%l+
OQ 4h8,
:5T=y @
public synchronized int write(byte[] b,int nStart,int nLen) ~EXCYUp4v
{ R~[~(`/S
int n = -1; 2Kr>93O
try{ S'ms>ZENC
oSavedFile.write(b,nStart,nLen); HUCJA-OZGL
n = nLen; >py[g0J
} d^!3&y&
catch(IOException e) RIO?rt;
{ vZ$E [EG}
e.printStackTrace (); VGxab;#,:3
} .j|uf[?h
/Qef[$!(
.Z"`:4O
return n; /4;A.r`;
} I2SH j6-
o&z[d
hDZyFRg
} v.>K )%`#
l;R8"L:,p\
U,6sR
/* ,`YBTU
**SiteInfoBean.java \QF0(*!!
*/ D Y4!RjJ47
package NetFox; Gx}`_[-
r#&JfAo
n|DMj[uT
public class SiteInfoBean { T9]0/>
xFM^-`7
GJ2ZK=/
private String sSiteURL; //Site's URL /'_<~A
private String sFilePath; //Saved File's Path (pP.*`JRv
private String sFileName; //Saved File's Name _JTK$\
private int nSplitter; //Count of Splited Downloading File "_dg$j`Y&&
Ij =NcP
]SPuNBsy)
public SiteInfoBean() vZ57 S13
{//nSplitter的缺省值为5 iD])E/
//default value of nSplitter is 5 z#P`m,~t0
this("","","",5); `{ HWk^
} k\j_hu
.\ya
WQiRbbX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5/h-Hr
{ T{`VUS/
sSiteURL= sURL; j;z7T;!i
sFilePath = sPath; yJ0%6],^g
sFileName = sName; B)L0hi
this.nSplitter = nSpiltter; 'r\RN\PT
Vky]In=
-Eq[J k
} `#8kJt
l Ib d9F
!]D`|HoW
public String getSSiteURL() UQ7]hX9
{ In1n.oRFn^
return sSiteURL; -KfK~P3PF
} 4e AMb
>b=."i
ONDO xXs
public void setSSiteURL(String value) h*!oHS~/l
{ >G%oWRk
sSiteURL = value; oJ3(7Sz
} +r;t]
tCGx]\
CnZEBAU
public String getSFilePath() 5$Kj#9g-#
{ M<NY`7$^
return sFilePath; 6<QC|>p
} t6mv
pnz:<V"Y(
:FH&#Eq~4
public void setSFilePath(String value) &IzNoB
{ w3sU& |N
sFilePath = value; aBG^Xhx
} *x]*%
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xLi3|^q
public String getSFileName() X/vyb^:U
{ $\/^O94-l
return sFileName; JN`$Fq+
} .`*]nN{
K*b* ]hf{
l:JVt`A4?
public void setSFileName(String value) ;fW~Gb?"
{ yTK3eK
sFileName = value; G}+@C]
} {I$iD
hwL`9.w
Z2})n -
public int getNSplitter() [XDV-6KCE.
{ ">3t+A
return nSplitter; ZS(%!+M
} +lVA$]d
'xG J;pY
!5?_)
public void setNSplitter(int nCount) _Z9d.-
{ .s,04xW\
nSplitter = nCount; gt(p%~
} }d>.Nj#zh
} QKq4kAaJ!
|%ZJN{!R
:3D6OBkB
/* &QW&K
**Utility.java _6r[msH"
*/ 9s[
package NetFox; 0!ZaR6
`O0Qtq.
c^pQitPv
public class Utility { "Ueq
9*K-d'm
P!IA;i
public Utility() ob2_=hQnC
{ 6D2ot&5WW
TlkhI
kp<Au)u
} [M%?[E}>
&oHr]=xA
//线程睡眠 +>*=~R
public static void sleep(int nSecond) ji\LC%U-
{ rXMc0SPk
try{ z\ONwMl
Thread.sleep(nSecond); \7*|u
} KU oAxA
catch(Exception e) _D?/$D7u#%
{ \mJR^t
e.printStackTrace (); U/s Z1u-
} h4 9q(085V
} eWex/ m
fiA8W
//日志 XxdD)I
public static void log(String sMsg) wEX<[#a-
{ o -)[{o\
System.err.println(sMsg); %$Py@g
} G7+{O7
z;?jKE p
=>3,]hnep
public static void log(int sMsg) gzSm=6Qw0
{ +6jGU'}[
System.err.println(sMsg); hFr+K1
} -=8f*K[W
} 8J$1N*J|
*aWh]x9TlU
%r.C9
/* |;)_-=L0P
**TestMethod.java >yn]h4M
*/ lt:&lIW,3
package NetFox; N}7b^0k
0n`Temb/
sH2xkUp
public class TestMethod { XP%_|Q2X
7_qsVhh]$E
|ZifrkD=
public TestMethod() ;^0ok'P\~9
{ ///xx/weblogic60b2_win.exe 047PlS
try{ Vn{;8hZ:a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >yT1oD0+x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !A% vR\
SiteFileFetch fileFetch = new SiteFileFetch(bean); CVkJMH_
fileFetch.start(); Z`GEF|eh
} G9QvIXRi
catch(Exception e){e.printStackTrace ();} H*3u]Ebh
Q#ksf h!D
DA>nYj-s
} piIzff
>d]-X]
-#/DK
public static void main(String[] args) ]:?S}DRG
{ $E^sA|KcT
new TestMethod(); rDoMz3[w
} 1EQ:@1
} Lk#)VGk:
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