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"R_3[NC
} cG!\P:re
for(int i=0;i<nEndPos.length-1;i++) R|&jvG=|
{ H.ha}0J
nEndPos = nStartPos[i+1]; g{PEplk
} E$O-\)wY0
nEndPos[nEndPos.length-1] = nFileLength; -YvnX0j+
} !UHWCJ< <w
} x -;tV=E}
n vzk P{
by}C;eN
//启动子线程 ~]f6@n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q$,AQyBlqc
for(int i=0;i<nStartPos.length;i++) NJ]AxFG
{ `>ppDQaS)W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H!SFSgAu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -t#YL
nStartPos,nEndPos,i); *G rYB6MT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V[DiN~H
fileSplitterFetch.start(); B|WM;Y^
} _43'W{%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :/A7Z<u,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _(7f0p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w?#s)z4}g
nEndPos = " + nFileLength); Cb}I-GtO
// fileSplitterFetch[nPos.length-1].start(); ehTrjb3k
zSd!n
Ww=^P{q\
//等待子线程结束 Gxhr0'
//int count = 0; _v6x3 Z
//是否结束while循环 TXL!5, X_
boolean breakWhile = false; E P3Vz8^
jouA ]E
Q DVk7ks
while(!bStop) r7ebFJEf
{ bW-sTGjRD
write_nPos(); |hl:!j.t
Utility.sleep(500); vKO/hZBh
breakWhile = true; sP:nTpTsC
HPryq)z
*Jwx,wF}4
for(int i=0;i<nStartPos.length;i++) ldFR%v>9
{ zgNzdO/B
if(!fileSplitterFetch.bDownOver) =;Q:z^S
{ 3xIelTf*
breakWhile = false; /7N&4FrG
break; }3O 0nab
} qdnwaJ;&
} {gz-w|7
if(breakWhile) 2A=q{7s
break; ]?G|:Kx$y%
xmNs%
V O\g"Yc
//count++; sOJXloeO[6
//if(count>4) rnyXMt.q
// siteStop(); ;rRV=$y
} 38mC+%iC
b#nI#!p'
xyD2<?dGUb
System.err.println("文件下载结束！"); $c{fPFe-
} EVlj#~mV
catch(Exception e){e.printStackTrace ();} AqiH1LAE
} $GR rTC!
9?iA~r|+
5szJ.!(
//获得文件长度 \ )WS^KR%
public long getFileSize() $35C1"
{ F|jl=i
int nFileLength = -1; riZ :#I
try{ N7u|< 0[
URL url = new URL(siteInfoBean.getSSiteURL()); >[2;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jiejs*
httpConnection.setRequestProperty("User-Agent","NetFox"); S6g_$Q7
?$K.*])e
YK\pV'&+
int responseCode=httpConnection.getResponseCode(); j1rR3)oP
if(responseCode>=400) jp;]dyU
{ 4/ WKR3X
processErrorCode(responseCode); /\{emE\]
return -2; //-2 represent access is error ?9;CC]D
} lc8g$Xw3
%*NED zy
ff;~k?L
String sHeader; P;`Awp?
jF-:e;-
9}wI@
for(int i=1;;i++) 43 vF(<r&f
{ ..kFn!5(g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5sANF9o!
//Utility.log(in.readLine()); %:s+5*SKe
sHeader=httpConnection.getHeaderFieldKey(i); *_Vv(H&
if(sHeader!=null) C*}PL
{ W#+f2 RR
if(sHeader.equals("Content-Length")) -2[#1S*
{ eEBo:Rc9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~N%+ZXh&E
break; hFo29oN
} A`#?Bj
} eBH:_Ls_-^
else dF[|9%)
break; hF{gN3v5
} d>?C?F
} 9Fy'L#%
catch(IOException e){e.printStackTrace ();} le' Kp V
catch(Exception e){e.printStackTrace ();} OwT_W)$
A=0{}B#
Y7zs)W8xTT
Utility.log(nFileLength); Q6HghG
A%2B3@1'q
HC}vO0X4
return nFileLength; X}xf_3N "
} Wco2i m
EDz;6Z*4N
@ x .`z
//保存下载信息（文件指针位置） E~#G_opQA
private void write_nPos() ] s^7c
{ Ab]tLz|Z
try{ Dw/vXyZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); "F}dZ
output.writeInt(nStartPos.length); R`Fgne$4
for(int i=0;i<nStartPos.length;i++) S6}_N/;6~
{ 3"zPG~fY{
// output.writeLong(nPos); {?Nm"#
output.writeLong(fileSplitterFetch.nStartPos); I-}ms
output.writeLong(fileSplitterFetch.nEndPos); eKy!Pai
} G pI4QzR
output.close(); t V( WhP
} %W8iC%~
catch(IOException e){e.printStackTrace ();} \gA<yz-;N
catch(Exception e){e.printStackTrace ();} ?HRS*
} ImG8v[Q E
qFK.ULgP`
ht*(@MCr<
//读取保存的下载信息（文件指针位置） \i/HHP[%
private void read_nPos() ~&<t++ g
{ =
try{ IA<>+NS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vQ*RrHG?c
int nCount = input.readInt(); `kJ)E;v;3
nStartPos = new long[nCount]; Pjk2tf0j`
nEndPos = new long[nCount]; ^8EW/$k
for(int i=0;i<nStartPos.length;i++) xxyc^\$
{ $cK}Tlq
nStartPos = input.readLong(); A yr,
nEndPos = input.readLong(); p3Qls*
} z bYv}q
input.close(); 'iF%mnJ
} f]#\&"
catch(IOException e){e.printStackTrace ();} aPzn4}~/_
catch(Exception e){e.printStackTrace ();} u4IK7[=
} p@kRo#~l
$cIaLq
A"ATtid
private void processErrorCode(int nErrorCode) nhdZC@~E0
{ .SjJG67OyA
System.err.println("Error Code : " + nErrorCode); F \ls]luN
} \wD/TLS}
YTFU#F
26g]_Igq
//停止文件下载 (_|*&au J
public void siteStop() h$kz3r;b,"
{ r&m49N,d
bStop = true; _Iminet
for(int i=0;i<nStartPos.length;i++) iMJt8sd
fileSplitterFetch.splitterStop(); l99Lxgx=
>zqaV@T
4/|x^Ky>G
} Dc@O Mr
} sBB[u'h!
//负责部分文件的抓取 ?tY+P`S
**FileSplitterFetch.java u&#>)h
*/ ']TWWwj$
package NetFox; P4q5#r
u+Ix''Fn#%
dkz% Y]
import java.io.*; uUg;v/:
import java.net.*; #<< el;n
L&DjNu`!9
Sc]K-]1(H
public class FileSplitterFetch extends Thread { iq*im$9J
F$)l8}
2PYnzAsl
String sURL; //File URL &RYdSXM
long nStartPos; //File Snippet Start Position V\Gs&>
long nEndPos; //File Snippet End Position @JXpD8jn
int nThreadID; //Thread's ID O\.^H/
boolean bDownOver = false; //Downing is over %h@1lsm1+
boolean bStop = false; //Stop identical F|eWHw?t
FileAccessI fileAccessI = null; //File Access interface 'KA$^
KR#,6
sJ|pR=g)!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,Q56A#Y\
{ @KK6JyOTQ
this.sURL = sURL; {/]2~!
this.nStartPos = nStart; R|8vdZ%@
this.nEndPos = nEnd; 6&os`!
nThreadID = id; {lWVH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m;~}}~&vQ
} a5pl/d
vSR&>Q%X
$KbZ4bB[Bo
public void run() 4`Ud\Jm[s
{ ?OFa Q
while(nStartPos < nEndPos && !bStop) 3/`BK{
{ (p{%]M
8In\Jo$|q>
|-x-CSN
try{ n"htx|v
URL url = new URL(sURL); !CUl1L1DSi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8{jXSCP#
httpConnection.setRequestProperty("User-Agent","NetFox"); dhtH&:J<;
String sProperty = "bytes="+nStartPos+"-"; Q4m> 3I
httpConnection.setRequestProperty("RANGE",sProperty); 4j=3'Z|
Utility.log(sProperty); M5h r0R{
IFTNr2I
20V~?xs~
InputStream input = httpConnection.getInputStream(); = g{I`u
//logResponseHead(httpConnection); %PYO9:n
:s_>y_=g
K>DN6{hnV;
byte[] b = new byte[1024]; Cq!eAc
int nRead; vHf)gi}O|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =$J(]KPv!?
{ 4CF;>b f~
nStartPos += fileAccessI.write(b,0,nRead); Ncz4LKzt
//if(nThreadID == 1) #@B"E2F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =\< 7+nv
} _li3cXE
'hjEd.
h.X4x2(.
Utility.log("Thread " + nThreadID + " is over!"); ML_VD*t9
bDownOver = true; euB1}M
//nPos = fileAccessI.write (b,0,nRead); H7X-\K 1w
} -x+3nb|.
catch(Exception e){e.printStackTrace ();} G$>?UQ[
} ww^\_KGu7
} A0Mjk
wtek5C^
\Osu1]Jn>
//打印回应的头信息 R'v~:wNTNs
public void logResponseHead(HttpURLConnection con) syR"p,3EC
{ RE;A0E_3
for(int i=1;;i++) "#iJ/vy
{ _p*9LsN$L
String header=con.getHeaderFieldKey(i); I1fpX |
if(header!=null) j+_fHADq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BX?DI-o^h
Utility.log(header+" : "+con.getHeaderField(header)); 'GJB9i+a^
else *&I>3;~%^}
break; rRq60A
} ~</FF'Xz
} ]j3>=Jb;
"ioO_
bp?5GU&Uy
public void splitterStop() X`D2w:
{ h-P|O6@Ki
bStop = true; |'?vlUCd
} `NW/Z/_
V.*TOU{{xh
BD C DQ
} E@SFK=`
=K`.$R
\1<'XVS
/* L0wT:x*
**FileAccess.java ^o3,YH
*//文件访问(定位，写) aO&U=!
package NetFox; 5%Qxx\q
import java.io.*; *2zp>(%
BmX'%5ho
?),b902C
public class FileAccessI implements Serializable{ |Vpp'ipr
~qghw@Q~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t*(bF[?
RandomAccessFile oSavedFile; 0zr27ko
long nPos; L"bJ#0m
|owr?tC
a4,V(Hlm
public FileAccessI() throws IOException i|^Q{3?o#
{ .C^P6S2oJ
this("",0); huC{SzXM
} +Ryj82;59z
G WIsT\J
;b{#$#`=
public FileAccessI(String sName,long nPos) throws IOException ]pR?/3
{ arL>{mj
oSavedFile = new RandomAccessFile(sName,"rw"); 7H3v[ f^Q
this.nPos = nPos; [inlxJD
oSavedFile.seek(nPos); >-MnB
} WN'AQ~qA
$@z77td3
U?0|2hR~
public synchronized int write(byte[] b,int nStart,int nLen) H+[?{+"#@l
{ 1 (<n^\J(
int n = -1; eI1zRoIl-
try{ A%8 Q}s$<s
oSavedFile.write(b,nStart,nLen); +_]Ui| l
n = nLen; 7%^G]AFi
} JH.XZM&
catch(IOException e) P)Adb~r
{ h[remR#3\
e.printStackTrace (); PF~@@j
} kk=n&M
ZsP^<
k$kE5kh,S
return n; HgQjw!
} !eyLh&]5
mo| D
5T;LWS
} ahl|N`
gnp.!-
t=P+m
/* qd0G sr}j
**SiteInfoBean.java /!H24[tnk1
*/ y[ dBmTY
package NetFox; Orq/38:4G
u nv:sV#b
JG!B3^qB
public class SiteInfoBean { CPJ<A,V
doanTF4Da
|=}+%>y_
private String sSiteURL; //Site's URL &ivU4rEG
private String sFilePath; //Saved File's Path >#G%2Vp
private String sFileName; //Saved File's Name KtQs uL%
private int nSplitter; //Count of Splited Downloading File IO\1nB$0nb
N'2?Zb
J||g(+H>
public SiteInfoBean() HJl?@&l/
{//nSplitter的缺省值为5 5sY$
//default value of nSplitter is 5 ]KFh1
this("","","",5); [5P-K{Ko
} e)e(f"t6Q
qR@ESJ_
Lvf<g}?4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z[@ i/. I
{ t utk*|S
sSiteURL= sURL; !4p{b f
sFilePath = sPath; J*zzjtY( 1
sFileName = sName; Al yJ!f"Y
this.nSplitter = nSpiltter; l+Wux$6U
$J6 .0O
pz^S3fy
} 1clzDwW
\n_7+[=E
='"Yj
public String getSSiteURL() L0![SE>
{ [Hx}#Kds
return sSiteURL; !RKuEg4hQ
} 3/RwCtc
;#Po}8Y=
?T/4 =
public void setSSiteURL(String value) k4sV6f
{ ^2'Y=g>
sSiteURL = value; Y][12{I{
} LW<LgN"L-
V6merT79
ci;2XLAM
public String getSFilePath() mP^B2"|q
{ #eJfwc1JY
return sFilePath; ?xaUWD
} 4u5j 7`O
]O|>nTa
0/QDfA?
public void setSFilePath(String value) >v,X:B?+FL
{ od!44p]
sFilePath = value; 7@{%S~TN
} ^JY {<
!{l% 3'2
?c8~VQaQ
public String getSFileName() _f!ko<52
{ I[%IW4jJ
return sFileName; EP38Ho=[
} O8Mypv/C
m}yu4
QbdXt%gZe
public void setSFileName(String value) dg|+?M^9`
{ g+o$&'\
sFileName = value; ho>@ $9
} !8p>4|VM
xI<l1@
'wPX.h?
public int getNSplitter() ^$oa`B^2JM
{ Apu-9|oP
return nSplitter; ]:f.="
} ^?e[$}
fS}Eu4Xe
E]q>ggeNH
public void setNSplitter(int nCount) S:!5|o|
{ Cx;it/8+
nSplitter = nCount; }e7/F[c.U
} TD\TVK3P
} lz=DGm
g;Fdm5Q
|e8A)xM]wC
/* 6ud?US(
**Utility.java 5^uX!_r`
*/ _U}|Le@ e
package NetFox; 5{-Hg[+9
M0m%S:2
A]"6/Lr9P
public class Utility { ,GWa3.&.d
v_5O*F7)
)-+tN>Bb
public Utility() 7'+`vt#E
{ kYS#P(1
/;_$:`|/
gB#!g@
} ${Lrj}93
~/4j&IG
//线程睡眠 ~JZLWTEe
public static void sleep(int nSecond) eZ) |m
{ CMC p7-v
try{ GGHMpQ
Thread.sleep(nSecond); |%4nU#GoB
} h(2{+Y+
catch(Exception e) Gad&3M0r
{ []\-*{^r
e.printStackTrace (); ]UOzz1
} MeD/)T{G~
} ft8
++2a xRl
//日志 pz2E+o
public static void log(String sMsg) }Bh\N5G%
{ '1!%yKc0
System.err.println(sMsg); S%p,.0_
} ^p4`o>
\R&ZWJKh
>CCy2W^W
public static void log(int sMsg) s,J\nbj0h
{ f[zKA{R
System.err.println(sMsg); ,9|7{j|u
} v'L"sgW6I
} d;%~\+)x4
(|W6p%(
lS;S:- -F
/* \U]<HEc^
**TestMethod.java fpNq
*/ El`G<esX
package NetFox; }`whg8 fZ
'o]}vyz;
l7ES*==&@0
public class TestMethod { cmf*BkS
O,@QGUoA
,vi6<C\
public TestMethod() <c`,fd8
{ ///xx/weblogic60b2_win.exe _z^&zuO
try{ ^CwS'/fdN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); TFc/`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9MRe?
SiteFileFetch fileFetch = new SiteFileFetch(bean); {KqW<X6Hp
fileFetch.start(); ld~*w
} 5k_%%><: q
catch(Exception e){e.printStackTrace ();} IL8&MA%
C/"Wh=h6
ORo +]9)Yv
} tchpO3u,
MoC/xF&
NnZ_x>R
public static void main(String[] args) :v-,-3AG
{ mX SLH'
new TestMethod(); bxz6 >>
} tG,xG&
} YcaLc_pUx
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