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)); m^^#3*qa
} ![Vrbe P
for(int i=0;i<nEndPos.length-1;i++) 2J`LZS
{ [c99m:*+
nEndPos = nStartPos[i+1]; sr:hRQ27
} \ow(4O#
nEndPos[nEndPos.length-1] = nFileLength; q?f-h<yRQ
} -BsZw. 7P
} Mv7tK l
~"h V-3U
`Cu9y+t
//启动子线程 .;D'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^brh\M,:@
for(int i=0;i<nStartPos.length;i++) oK&G
{ pFwe&_u]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AUl[h&s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q2!RFtXV
nStartPos,nEndPos,i); Q%t _Epe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wJ7Fnj>u%
fileSplitterFetch.start(); ASNo6dP7
} E7]a#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (. ,{x)H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [bN_0T.YI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <H1e+l{8$
nEndPos = " + nFileLength); V("T9g
// fileSplitterFetch[nPos.length-1].start(); N/E=-&E8
]oC7{OoX
'qidorT>N
//等待子线程结束 wee5Nirw6
//int count = 0; b/=>'2f
//是否结束while循环 ?;go5f+X
boolean breakWhile = false; h0VeXUM;.
sWgzHj(c
1mx;b)4t
while(!bStop) @9MrTP
{ EFs\zWF
write_nPos(); a & 6-QVk
Utility.sleep(500); j!a&l
breakWhile = true; dp:5iuS
{|Fn<&G
V#+J4
for(int i=0;i<nStartPos.length;i++) f:9qId ;/M
{ L!2Ef4,wAz
if(!fileSplitterFetch.bDownOver) \(1WLP$2U
{ "04:1J`
breakWhile = false; Aac7km
break; [wUJ~~2#
} *0 ;|
} }i\_`~
if(breakWhile) JZD&u6tB
break; c$)!02
zM'2opiUY
T{ /\q 5
//count++; zc>LwX}<
//if(count>4) 0-U%R)Q
// siteStop(); J5\2`U_FZ
} FsfP^a
zZ])G
46c0;E\9
System.err.println("文件下载结束！"); 'ExQG$t
} "ScY'<
catch(Exception e){e.printStackTrace ();} 0&2&F=fOa<
} $H7T|`WI.,
a3BlydSlf
SvD:UG
//获得文件长度 )"^ )Nk
public long getFileSize() Y-*]6:{E
{ ;3sJ7%`v
int nFileLength = -1; )`m/vYKWL
try{ 5U(ry6fI=
URL url = new URL(siteInfoBean.getSSiteURL()); p%CcD]o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =]sM,E,n
httpConnection.setRequestProperty("User-Agent","NetFox"); 4)d#dy::\
P Z+Rz1x
Yo2n[
int responseCode=httpConnection.getResponseCode(); "H)D~K~*
if(responseCode>=400) Z`'&yG;U
{ XO4rrAYvW
processErrorCode(responseCode); u[coWaPsZ
return -2; //-2 represent access is error ldWr-
} .^uYr^(|[
4m/L5W:K
^g n7DiIPH
String sHeader; K]Q1VfeL=
eHI7= [h
Jgf=yri
for(int i=1;;i++) gz"I=9
{ JA^Y:@<{/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4B@L<Rl{\
//Utility.log(in.readLine()); },tn
sHeader=httpConnection.getHeaderFieldKey(i); [Ma d~;
if(sHeader!=null) U~{sJwB
{ y Ide]
if(sHeader.equals("Content-Length")) wqf^n-Ze
{ sVT\e*4m}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =h}IyY@o
break; %%k`+nK~
} k&\ 6SK/
} lnRbvulH
else /'>#1J|TlK
break; '~kAsn*/
} dK?vg@|'
} iY4FOt7\
catch(IOException e){e.printStackTrace ();} NxQ+z^o\
catch(Exception e){e.printStackTrace ();} pL)o@-k#%
qi-!iT(fe
h8tKYm
Utility.log(nFileLength); wr;8o*~
F /% 5 r{
l+i9)Fc<i
return nFileLength; !3#*hL1fy
} "]D2}E>U;
6/eh~ME=
L&SlUXyt.c
//保存下载信息（文件指针位置） -!z,t7!
private void write_nPos() :g=z}7!s
{ Ym"Nj
try{ X'h J&-[P
output = new DataOutputStream(new FileOutputStream(tmpFile)); K~Hp%.
output.writeInt(nStartPos.length); @-Js)zcl q
for(int i=0;i<nStartPos.length;i++) m>@ *-*8k
{ O&u[^s/^
// output.writeLong(nPos); a).bk!G
output.writeLong(fileSplitterFetch.nStartPos); Z2u5n`K
output.writeLong(fileSplitterFetch.nEndPos); 2kU=9W6ND
} Td>Lp=0rU
output.close(); f_GqJ7Gk]
} N_"mC^Vx
catch(IOException e){e.printStackTrace ();} , H_Cn1l
catch(Exception e){e.printStackTrace ();} 1]vrpJw
} 7ehs+GI
7'9~Kx&+
C~dD'Tq]
//读取保存的下载信息（文件指针位置） i@}/KT
private void read_nPos() U[UjL)U
{ !mLYW
try{ Q>}*l|Ci
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I`e|[k2
int nCount = input.readInt(); J 4EG
nStartPos = new long[nCount]; +iYy^oXxw
nEndPos = new long[nCount]; 7+vyN^XJ"5
for(int i=0;i<nStartPos.length;i++) {qHf%y&[
{ &jHnM^nQ
nStartPos = input.readLong(); F&om^G'U
nEndPos = input.readLong(); Jr4^@]78o<
} p%v+\T2r
input.close(); RvT>{G~
} sOBy)vq?\
catch(IOException e){e.printStackTrace ();} (PmaVwF
catch(Exception e){e.printStackTrace ();} "e\:Cq>\
} /HmD/E\
FF"`F8-w>Z
Z ^tF
private void processErrorCode(int nErrorCode) } 1>i
{ W\?_o@d
System.err.println("Error Code : " + nErrorCode); 7Bhi72&6
} c`(]j w
g&30@D"
Gmi$Nl!~
//停止文件下载 oX9rpTi
public void siteStop() wv8WqYV
{ KC-q]
bStop = true; *VFUC:
for(int i=0;i<nStartPos.length;i++) |-c)OS3#D
fileSplitterFetch.splitterStop(); /~Q2SrYH
yI 6AafS~
W c"f
} 'bpx
} _f8<t=R
//负责部分文件的抓取 v]tbs)x;h
**FileSplitterFetch.java QDg\GA8|
*/ \y9( b
package NetFox; @,RrAL}|
?6gC;B
N!}r(Dd*
import java.io.*; 9?M><bBX
import java.net.*; \i-HECc"U
(@H'7,
)h0F'MzW
public class FileSplitterFetch extends Thread { pbe" w=<
'W/E*O6BY
I-Ya#s#m
String sURL; //File URL lth t'|
long nStartPos; //File Snippet Start Position W`KRaL0^
long nEndPos; //File Snippet End Position j`Xe0U<
int nThreadID; //Thread's ID R&BbXSIDX
boolean bDownOver = false; //Downing is over vt" 7[!O
boolean bStop = false; //Stop identical ptXLWv`
FileAccessI fileAccessI = null; //File Access interface 4A_}:nU
%z&=A%'a
]R8}cbtU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ROr..-[u
{ Pd@y+|
this.sURL = sURL; *t'qn
this.nStartPos = nStart; TM8WaH
this.nEndPos = nEnd; S"iz fQ@
nThreadID = id; UGNFWZ c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {]aB3
} &n.7~C]R
\h DH81L
n"'1.
public void run() Htseu`>_$
{ 0i2ZgOJ
while(nStartPos < nEndPos && !bStop) DbdxHuKa>
{ cCd2f>EHw
);*A$C9RA
E}aTH
try{ 5fK#*(x
URL url = new URL(sURL); Y!C=0&p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `gIlS^Q
httpConnection.setRequestProperty("User-Agent","NetFox"); M~Yho".
String sProperty = "bytes="+nStartPos+"-"; o:<gJzg
httpConnection.setRequestProperty("RANGE",sProperty); ,[rh7_
Utility.log(sProperty); `CP}1W>
z}vgp\cuT
CY&Z*JI"'B
InputStream input = httpConnection.getInputStream(); P%8zxU;
//logResponseHead(httpConnection); SbmakNWJ}
kETu@la}
3[: |)i)
byte[] b = new byte[1024]; iEG`+h'
int nRead; fdIk{o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5gV%jQgkC
{ =IH z@CU
nStartPos += fileAccessI.write(b,0,nRead); !xm87I
//if(nThreadID == 1) $F!)S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^1rw\Zp
} , 4Vr,?"EO
2 w2JFdm
Dz4fP;n
Utility.log("Thread " + nThreadID + " is over!"); ~l~ai>/
bDownOver = true; L3^WI( 8m
//nPos = fileAccessI.write (b,0,nRead); DW^E46k)A
} SrPZ^NF
catch(Exception e){e.printStackTrace ();} -MrEJ
} x?0ZzB),
} s)dN.'5/
Aen)r@Y:
u:r'&#jb~@
//打印回应的头信息 1=x4m=wV
public void logResponseHead(HttpURLConnection con) x j6-~<
{ _@[M0t}g_
for(int i=1;;i++) $~xY6"_}!!
{ w:l/B '%]Y
String header=con.getHeaderFieldKey(i); &BnK[Q8X
if(header!=null) F.)b`:g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6$qn'K$
Utility.log(header+" : "+con.getHeaderField(header)); SqL8MKN)
else )J&1uMp{
break; FI1R7A
} q(0V#kKC
} hX\z93an
eqK6`gHa6
B[:-SWd
public void splitterStop() 9ZjSM,+
{ `<>Emc8Z
bStop = true; nmlQ-V-
} : [o0Va2 d
k23*F0Dv
Vk/CV2
} mAkR<\?iTF
*Z*4L|zT
d5gYJ/Qv
/* }Wf\\
**FileAccess.java 1{B^RR.
*//文件访问(定位，写) Fj<#*2{]B
package NetFox; "G\OKt'Z
import java.io.*; HCHZB*r[
Fw!CssW
W)I)QinOH
public class FileAccessI implements Serializable{ V QE *B
4R5+"h:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V:*QK,
RandomAccessFile oSavedFile; M#II,z>q
long nPos; 9V*h:[6a(
ZSj^\JU
@N?A0S/
public FileAccessI() throws IOException "71@WLlN
{ uop|8n1
this("",0); f5jxF"oGNo
} Q70LQCms
%\8E{M:
x{IxS?.j+
public FileAccessI(String sName,long nPos) throws IOException Z)cGe1?q
{ gR)T(%W
oSavedFile = new RandomAccessFile(sName,"rw"); YNCQPN\v`1
this.nPos = nPos; |,c\R"8xS
oSavedFile.seek(nPos); :d7Ju.*J
} `N%q^f~
^<fN
oTj9/r
public synchronized int write(byte[] b,int nStart,int nLen) AyZL(
{ P#5&D*`}h
int n = -1; `~'yy q
try{ M&Aeh8>uX
oSavedFile.write(b,nStart,nLen); $i&u\iL
n = nLen; Iuk!A?XV
} '&{`^l/MH
catch(IOException e) |T:'G
{ e1ru#'z
e.printStackTrace (); >gqM|-uY
} 1Wzm51RU
.JIn(
XPnN"Y"y
return n; q~9Y&>D
} y'ULhDgq^B
O(BAw
u!TVvc
} L=W8Q8hf
[5$=G@ zf
Q C?*O?~#
/* ;E0Xn-o_
**SiteInfoBean.java _Wn5* Pi%Z
*/ -gZI^EII
package NetFox; _h1n]@ d5
FV|/o%XqK
]i\C4*
public class SiteInfoBean { Gz)]1Z{%$
,zmGKn#n2
z7X[$T$V
private String sSiteURL; //Site's URL _:4n&1{.E
private String sFilePath; //Saved File's Path #Pi}2RBRu
private String sFileName; //Saved File's Name DuJbWtA
private int nSplitter; //Count of Splited Downloading File ,&$w*D%
nzI}w7>VU
_l}"gUtiw
public SiteInfoBean() cX'&J_T+
{//nSplitter的缺省值为5 c%,~1l
//default value of nSplitter is 5 *G)=6\
this("","","",5); jFYv4!\ju
} ^DZ(T+q,
@&!HMl
=bm<>h7.)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z>HeM Mei
{ N- E)b
sSiteURL= sURL; Dg](?^
sFilePath = sPath; C]{:>= K
sFileName = sName; r9@4-U7v&
this.nSplitter = nSpiltter; xB=~3
~$7fU
<{U "0jY!9
} HS!O;7s'
-' 7I|r
:G?6Hl)~)
public String getSSiteURL() m}Z=m8
{ >P*wK9|(
return sSiteURL; JA'C\
} NbyVBl0=
cY1d6P0
*3_@#Uu7
public void setSSiteURL(String value) +/,J$(
{ nY7 ZK
sSiteURL = value; !o A,^4(
} 7I>@PVN
C^vB&3ghi
fbaQXM
public String getSFilePath() v{7Jzjd
{ 6BT o%
return sFilePath; ;Js-27_0
} fg1_D
rap`[O|l=
8t3,}}TJ
public void setSFilePath(String value) "0al"?
{ G[7Z5)2B
sFilePath = value; Ph(bgQg
} %j4
&HdzbKO=
I8=p_Ie
public String getSFileName() Si[:l
{ FF]xwptrx
return sFileName; uH'n.d"WG
} 6J3:[7k=&
*T(z4RVg
g~EJja;
public void setSFileName(String value) FSnF>3kj-
{ WZkAlg7Z
sFileName = value; lFMQT ;
} @SA:64 9
"/v{B?~%!
~4HS 2\
public int getNSplitter() *z-Mr~V
{ `/en&l
return nSplitter; -X#Zn>#
} =bt/2nPV
{ir8n731p
'xO5Le(=M
public void setNSplitter(int nCount) >U/m/H'
{ #sLyU4QV
nSplitter = nCount; tE"aNA#=
} X"yjsk
} 1an?/j,
s&-m!|P
tz0_S7h
/* q.]>uBAQ?
**Utility.java y^"[^+F3 .
*/ 3R!?r^h
package NetFox; UOTM>d1P
d^5OB8t
kaBP&6|Z
public class Utility { "o+E9'Dm
I"/p^@IX
rVU::C+-
public Utility() !KiN} p
{ l#!p?l
{<f_,Nlc
CF|c4oY82
} 4{!7T
-8;@NAUa
//线程睡眠 NYS|fa
public static void sleep(int nSecond) {Vy2uow0
{ }cDw9;~D
try{ laVqI|0q
Thread.sleep(nSecond); [v7)xV@c
} 5&}~W)"9
catch(Exception e) iwJeV J
{ ^{L/) Xy5
e.printStackTrace (); :xdl I`S
} EyJWi<
} Eg&oAY.U
#:E}Eby/6I
//日志 <=fYz^|XT
public static void log(String sMsg) w9QY2v,U
{ nW1Obu8x|
System.err.println(sMsg); rkw^RW^
} ILsw'
tYE\tbCO'
>f7;45i
public static void log(int sMsg) Kh{C$b
{ @=@7Uu-
System.err.println(sMsg); a`]Dmw8@
} BEn,py7
} Q a(>$.h
N%8O9Dp8;
&j4 1<A
/* crx8+
**TestMethod.java 5X2&hG*
*/ TFrZ+CcWp2
package NetFox; MfzSoxCb
3LT[?C]H$
s zgq7
public class TestMethod { E1p?v!
2D,EWk/4
fTn
public TestMethod() eC+S'Jgf
{ ///xx/weblogic60b2_win.exe 2"Oj* ;
try{ r*e<`Is
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9 F"2$;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mIJYe&t7)
SiteFileFetch fileFetch = new SiteFileFetch(bean); AF-4b*oB
fileFetch.start(); ZHQa}C+
} N@Ie VF
catch(Exception e){e.printStackTrace ();} aZK%?c
ko-:)z
E_t ^osY&
} Q};g~b3
u;{,,ct
.<GU2&;!
public static void main(String[] args) sn.Xvk%75
{ mGf@J6wGz
new TestMethod(); :nk$?5ib
} u19d!#g
} 7#\\Ava$T
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