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)); -?'r_t
} Y<%$;fx$Sx
for(int i=0;i<nEndPos.length-1;i++) LHKawEZ
{ X*1vIs;[@
nEndPos = nStartPos[i+1]; G%-[vk#]
} )nJs9}( 0
nEndPos[nEndPos.length-1] = nFileLength; ~\<Fq\.x
} 5`*S'W}\>
} K+TRt"W8&s
i,M<}e1
!.H< dQS
//启动子线程 Xa#`VDh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "zJ1vIZY
for(int i=0;i<nStartPos.length;i++) xRq|W4ay
{ B<J}YN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^aN;M\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?SRG;G1
nStartPos,nEndPos,i); o X )r4H?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wd?(B4{
fileSplitterFetch.start(); ?kX$Y{M}
} 1om:SHw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p]:5S_$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |7 ]v&?y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E$=!l{Ms
nEndPos = " + nFileLength); EyA}
// fileSplitterFetch[nPos.length-1].start(); j8WnXp_
qk{2%,u$@{
r ,D T>
//等待子线程结束 .&=nP?ZPC6
//int count = 0; .Ebg>j:\
//是否结束while循环 jQ@z!GirT
boolean breakWhile = false; (e6JI]tz{
lX/s Q
b=horvs/!
while(!bStop) F\F_">5
{ @~hiL(IR'
write_nPos(); @v\Osp t=
Utility.sleep(500); lt`(R*B%
breakWhile = true; _Je<_pl!D
b/HhGA0
wO/}4>\
for(int i=0;i<nStartPos.length;i++) 4UT%z}[!
{ =<MSM\Rb
if(!fileSplitterFetch.bDownOver) zs:OHEZw
{ x;dyF_*;
breakWhile = false; Xd@ -
break; +KgLe>-}
} ozwPtF5
} UUJbF$@;
if(breakWhile) 3&:Us|}
break; l8 k@.<nCO
\/J>I1J
#kjN!S*=
//count++; c1B<9_
//if(count>4) | s%--W
// siteStop(); F9p'|-
} ;NQ9A &$)
/#lhRNX
GcaLP*%>B
System.err.println("文件下载结束！"); "c` $U]M%
} 2kb<;Eh`G
catch(Exception e){e.printStackTrace ();} 88x_}M^Fnl
} gpDH_!K
&~)PB |
Evu`e=LaG
//获得文件长度 2%P{fJbwd
public long getFileSize() IA I!a1e!
{ ^=`7]E[p
int nFileLength = -1; o~<Xc
try{ -d5b,leC^
URL url = new URL(siteInfoBean.getSSiteURL()); >>/|Q:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p^QZGu-.W
httpConnection.setRequestProperty("User-Agent","NetFox"); dJxdrs
1c8Nr&Jl
(37dD!
int responseCode=httpConnection.getResponseCode(); qg1s]c~0u
if(responseCode>=400) /iURP-rl
{ U|SF;T .
processErrorCode(responseCode); 3+vbA;R
return -2; //-2 represent access is error nMm4fns
} VZuluV
U[7 &
8p D$/
String sHeader; &iKy
~+DPq|-O
%d?.v_Hu0
for(int i=1;;i++) kq|(t{@Rp
{ X.}i9a 6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v2eLH:6
//Utility.log(in.readLine()); fk%W07x!
sHeader=httpConnection.getHeaderFieldKey(i); ayF+2(vch)
if(sHeader!=null) @cYb37)q=
{ iB4`w\-o
if(sHeader.equals("Content-Length")) fghw\\]3
{ wO<.wPa`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }@6Tcn1
break; ]90BIJ]*c
} ? nx3#<
} V'b$P2 ?^
else n vzk P{
break; (4]M7b[S$
} _EPfeh;
} FgwIOpqE*
catch(IOException e){e.printStackTrace ();} JR6r3W
catch(Exception e){e.printStackTrace ();} {:=sCY!
IQZ/8UwB
phCItN;
Utility.log(nFileLength); $?P5A E
Y#e,NN
<|-da&7
return nFileLength; ,J;Cb}
} W*2d!/;7>
#hMS?F|
jD}G9=[$1
//保存下载信息（文件指针位置） wWkMvs
private void write_nPos() vJ,r}$H3
{ I<+EXH%1,
try{ Nyx)&T&I
output = new DataOutputStream(new FileOutputStream(tmpFile)); *jQ?(Tf
output.writeInt(nStartPos.length); [D%(Y ~2
for(int i=0;i<nStartPos.length;i++) ^(F@#zN}
{ [?>\]
// output.writeLong(nPos); Q DVk7ks
output.writeLong(fileSplitterFetch.nStartPos); r7ebFJEf
output.writeLong(fileSplitterFetch.nEndPos); ]`eP"U{
} )kMF~S|H
output.close(); 0RZ[]:(
} i(qZ#oN
catch(IOException e){e.printStackTrace ();} UaCfXTG
catch(Exception e){e.printStackTrace ();} c-VIpA1
} zgNzdO/B
=;Q:z^S
<uG6!P
//读取保存的下载信息（文件指针位置） OLS/3c z
private void read_nPos() rdH3!
{ m?O~(6k@C
try{ -DuI 6K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'fjouO
int nCount = input.readInt(); +)xjw9b
nStartPos = new long[nCount]; a%nf )-}|
nEndPos = new long[nCount]; dtj+ avG
for(int i=0;i<nStartPos.length;i++) xlcL;e&^P
{ x^zw1e,y
nStartPos = input.readLong(); FUVp}>#U
nEndPos = input.readLong(); b#nI#!p'
} xyD2<?dGUb
input.close(); :%-w/QwTR
} ~pT1,1
catch(IOException e){e.printStackTrace ();} fc&djd`FuX
catch(Exception e){e.printStackTrace ();} .H@b zm
} Cs4ks`Z18
KAJR.YNm
5) q_Aro
private void processErrorCode(int nErrorCode) ;kzjx%h
{ nIr:a|}[
System.err.println("Error Code : " + nErrorCode); ,njlKkFw^Z
} 9OYyR
eo*l^7
W3zYE3DZf
//停止文件下载 h! Bg}B~
public void siteStop() YK\pV'&+
{ UgLFU#
bStop = true; A.vf)hO
for(int i=0;i<nStartPos.length;i++) B*(BsXQLY
fileSplitterFetch.splitterStop(); M5a&eO
\E=MV~:R
&\=Tm~
} U8.V Rn
} >4#:qIU
//负责部分文件的抓取 #w3J+U 6r
**FileSplitterFetch.java ",xTgB3?V
*/ [vY#9W"!
package NetFox; +MZI\>
%VGW]!QR
YkFAu8b>
import java.io.*; $1$0M
import java.net.*; IH&0>a
k;B[wEW@
ur.krsU
public class FileSplitterFetch extends Thread { f^-ot@w
g>@a
:R`e<g~4
String sURL; //File URL DaQ+XUH?
long nStartPos; //File Snippet Start Position %JHv2[r^P
long nEndPos; //File Snippet End Position .{t*v6(TP
int nThreadID; //Thread's ID HSWki';G
boolean bDownOver = false; //Downing is over iZLy#5(St
boolean bStop = false; //Stop identical F$-fj "jC
FileAccessI fileAccessI = null; //File Access interface "IB36/9
$%^](-
:c|Om{;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =;4K5l{c
{ !?>QN'p.b
this.sURL = sURL; k'_f?_PBu
this.nStartPos = nStart; twu,yC!
this.nEndPos = nEnd; qyxd9Lk1
nThreadID = id; z4 <_>)p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dl"=ZI '^
} 0hhxTOp
\WBO(,]V
Y=4 7se=h"
public void run() n"`V| UTHP
{ rFGPS%STS
while(nStartPos < nEndPos && !bStop) k33\;9@k
{ Ph%{h"
SXP(C^?C
'pT13RFD
try{ o5j6(`#;
URL url = new URL(sURL); I(Qz%/Ox
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /* qx5$~
httpConnection.setRequestProperty("User-Agent","NetFox"); S]ayH$w\Q
String sProperty = "bytes="+nStartPos+"-"; G pI4QzR
httpConnection.setRequestProperty("RANGE",sProperty); cxQAp
Utility.log(sProperty); @dk-+YxG
h (q,T$7W
\gA<yz-;N
InputStream input = httpConnection.getInputStream(); 8h0CG]
//logResponseHead(httpConnection); z"T+J?V/
Gh/nNwyu<
#6vf:94
byte[] b = new byte[1024]; bf@g*~h@
int nRead; Y6&v&dA;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'YB[4Q /0
{ ZG0^O"B0
nStartPos += fileAccessI.write(b,0,nRead); 6}m`_d?
//if(nThreadID == 1) 8^^ 1h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \I:27:iAL
} P JATRJ1.
6lCpf1>6@
jC_'6sc`
Utility.log("Thread " + nThreadID + " is over!"); mZ2CGOR
bDownOver = true; :{N*Z}]
//nPos = fileAccessI.write (b,0,nRead); z bYv}q
} {f\wIZ-K A
catch(Exception e){e.printStackTrace ();} L{P'mG=4
} S't9F
} c+&Kq.~K
V]; i$
1Xo0(*O
//打印回应的头信息 y%ij)vQY
public void logResponseHead(HttpURLConnection con) .SjJG67OyA
{ hcj]T?
for(int i=1;;i++) }3A~ek#*~
{ CV\^gTPmx
String header=con.getHeaderFieldKey(i); Y~g\peG7
if(header!=null) >t)Pcf|s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g=[OH
Utility.log(header+" : "+con.getHeaderField(header)); C{}PO u
else 4VZI]3K,
break; :P}3cl_
} t 86w&
} 4P[MkMoC
i_Hm?Bi!F
5"@>>"3U
public void splitterStop() #lrwKHZ+
{ VS/M@y_./
bStop = true; >({qgzV`
} W,NqevXo:
w") G:K
6`O,mpPu4G
} tu<<pR>
{7jim
$/s"It
/* m{Vd3{H40
**FileAccess.java pdRM%ug
*//文件访问(定位，写) ;O% H]oN
package NetFox; 5PO_qr=Hx
import java.io.*; =4MTb_
g}v](Q
zawu(3?~)5
public class FileAccessI implements Serializable{ y62f{ks_/
D#L(ZlD4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,Q56A#Y\
RandomAccessFile oSavedFile; ]B,tCBt
long nPos; `=H*4I-"
I8?
3~T ~Bs
public FileAccessI() throws IOException F*[E28ia&
{ a5pl/d
this("",0); %jzTQ+.%]^
} wx*?@f>u^
-y-}g[`
V?j,$LixY
public FileAccessI(String sName,long nPos) throws IOException (p{%]M
{ YK6LJv}
oSavedFile = new RandomAccessFile(sName,"rw"); 7S}0Kuk)
this.nPos = nPos; IqYJ
oSavedFile.seek(nPos); 4W"A*A
} 6?F88;L
]UkH}Pt'3
2.aCo, Kb;
public synchronized int write(byte[] b,int nStart,int nLen) u9"yU:1keb
{ RG{T\9]n
int n = -1; d}4NL:=&
try{ $_"u2"p
oSavedFile.write(b,nStart,nLen); ;|WUbc6&g
n = nLen; d5l42^Z
} /eQAGFG
catch(IOException e) d$3rcH1
{ aDdGhB
e.printStackTrace (); T&_&l;syA
} )k=KLQ\b
'hjEd.
Bib<ySCre
return n; {!|4JquE_
} 9,'m,2%W
X%'z
G$>?UQ[
} .2fvRN92
MM@,J<
%*gf_GeM
/* 23):OB>S`
**SiteInfoBean.java VO:4wC"7
*/ O6hzOyNX@
package NetFox; ?$6H',u
fs ufYIf
DEZww9T2Qs
public class SiteInfoBean { z?\it(
j+_fHADq
-'$ob~*
private String sSiteURL; //Site's URL *DPX4P
private String sFilePath; //Saved File's Path *SNdU^!
private String sFileName; //Saved File's Name XYo,5-
private int nSplitter; //Count of Splited Downloading File "r&,#$6W6
O=2|'L'h!
U=G49~E
public SiteInfoBean() +X/a+y-
{//nSplitter的缺省值为5 Xfc$M(a K{
//default value of nSplitter is 5 wD9K\%jIr!
this("","","",5); ZIx-mC5
} R])Eg&
I`0-q?l
2l)"I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E@SFK=`
{ 3IMvtg
sSiteURL= sURL; iqDyE*a
sFilePath = sPath; {U=J>#@G
sFileName = sName; DO:,PZX
this.nSplitter = nSpiltter; 63W;N7@
~*iF`T6
BmX'%5ho
} z+"$G
6j6CA?|
}emUpju<C
public String getSSiteURL() gI^&z
{ -%`~3*L
return sSiteURL; :lB*kmg
} L"bJ#0m
1b9S";ct0
Ooz,?wU6
public void setSSiteURL(String value) E'LI0fr
{ u<S`"MR:J
sSiteURL = value; c|?(>
} aN0[6+KP;
K}l3t2uk
E`fG9:6l]
public String getSFilePath() yvB]rz} i
{ Z Ts*Y,
return sFilePath; c<$<n
} N!K%aH~O
?6:qAFw
60+zoL'
public void setSFilePath(String value) B"GC|}N)v
{ H a!,9{T
sFilePath = value; Y7t#)?
} /I7V\
6(8F4[D
=<n ]T;
public String getSFileName() &BPYlfB1
{ x4q}xwH
return sFileName; <&E}db
} $Z G&d
!eyLh&]5
mo| D
public void setSFileName(String value) Q#p)?:o/
{ w0BphK[
sFileName = value; l?m"o-Gp3
} ^EUR#~b5iy
+VUkV-kP
=z# trQ{
public int getNSplitter() Dd?G4xUG
{ 8T3,56>
return nSplitter; `jE[Xt"@
} \ja6g
R{@saa5I(>
B[uyr)$
public void setNSplitter(int nCount) d7V/#34
{ OWvblEBF
nSplitter = nCount; IO\1nB$0nb
} &hWELZe0vv
} `LkrG9KV{
*Dp&;,b
%],BgLhS.
/* MJ:c";KCq0
**Utility.java u2#q7}
*/ wC{sP"D
package NetFox; |ty&}'6C
;dzy5o3
oKn$g[,SJh
public class Utility { fV"Y/9}(
+ f6LG 0q
>|SIqB<%:
public Utility() 0!\gK<,z
{ $J6 .0O
B /;(#{U;
_A,_RM$Y
} Mk*4J]PP
`:C1Wo^<
//线程睡眠 \'y]mB~k
public static void sleep(int nSecond) $1])>m_ct
{ 3/RwCtc
try{ 8-G )lyfj
Thread.sleep(nSecond); .B`$hxl*0c
} dy6zrgxygP
catch(Exception e) b~^'P
{ I=L["]
e.printStackTrace (); &kb~N-
} I$"Z\c8;
} NO*,}aeG
t=7Gfv
//日志 XIIq0I
public static void log(String sMsg) #4AU&UM+i
{ 12^uu)6Xm,
System.err.println(sMsg); +C`!4v\n
} 5X0ex.
L\4rvZa
"r6qFxY
public static void log(int sMsg) |Y"XxM9
{ U4d7-&U
System.err.println(sMsg); _f!ko<52
} g=td*S
} =o(}=T>:"
[],[LkS
XGZZKvp
/* WoXAOj%iW
**TestMethod.java +Ug &
*/ rai'x/Ut}+
package NetFox; x)?V{YAL
HK[%'OQ
`*U@d%a
public class TestMethod { Apu-9|oP
:Ou~?q%X
4<s;xSCL
public TestMethod() i7dDklj4
{ ///xx/weblogic60b2_win.exe pqg2#@F.
try{ <~|n}&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IEm?'o:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7}xQ4M\u$
SiteFileFetch fileFetch = new SiteFileFetch(bean); z_(l]Ern}
fileFetch.start(); }P2*MrkcHB
} 7Ydqg&
catch(Exception e){e.printStackTrace ();} -, +o*BP
f?Ex$gnI
%>K(IRpMW
} /,:cbpHsu
\WE/#To
vT5GUO{5
public static void main(String[] args) 5^uX!_r`
{ {ZUk!o>m@
new TestMethod(); :/6:&7s
} yi^X?E{WnX
} !wAnsK
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