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)); ,z1# |Y
} n/$BdFH
for(int i=0;i<nEndPos.length-1;i++) YL){o$-N"J
{ G8u8&|
nEndPos = nStartPos[i+1]; ^l$(-#'y
} YD.3FTNGC
nEndPos[nEndPos.length-1] = nFileLength; [ R~+p#l+Q
} h4?+/jk7
} f@LUp^Z/v
wB9IP{Pf
KNY<"b
//启动子线程 Xid>8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DIk$9$"<x
for(int i=0;i<nStartPos.length;i++) X'kw5P!sq
{ ]2h[.qa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~%#?;hJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *}/xy SH3
nStartPos,nEndPos,i); &51/Pm2O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l06 q1M 3
fileSplitterFetch.start(); "b1_vA]03
} I.KYWs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L+I[yJY:!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q~xR'G[N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1'aS2vB9
nEndPos = " + nFileLength); xR_]^Get
// fileSplitterFetch[nPos.length-1].start(); .z[+sy_
g!~j Wn?A
gKYn*
//等待子线程结束 uXhp+q\
//int count = 0; "*7I~.7U(*
//是否结束while循环 e\yj>tQJg
boolean breakWhile = false; UD9h5PgT
s|,]Nb=z/
ZM|>Va/X
while(!bStop) b%oma{I=.c
{ G x,D'H'
write_nPos(); 1c}'o*K_%
Utility.sleep(500); nn=JM7e\9
breakWhile = true; 1Rczf(,aT
fLD9RZ8_
_eO]awsA
for(int i=0;i<nStartPos.length;i++) [w{ZP4d>
{ whLske-
if(!fileSplitterFetch.bDownOver) R +\y".
{ Rp@u.C<
breakWhile = false; ux=a9
break; yBl<E$=
} 8vT:icl
} 2sU"p5 j
if(breakWhile) BKDWd]KEf
break; 4U6{E#
RtIc:ym
{xH \!!"T
//count++; /ZzlC#`
//if(count>4) %kcg#p+tE
// siteStop(); RU{}qPs?
} ;zCHEz
TuF:m"4
B"qG-ci
System.err.println("文件下载结束！"); 5=?&q 'i
} ?DRC! 9o^
catch(Exception e){e.printStackTrace ();} ]!A;-m
} K[ \z'9Q
hV,3xrm?P
*jJ62-o
//获得文件长度 VLO>{"{'
public long getFileSize() kEXcEF_9P
{ p0tv@8C>
int nFileLength = -1; v4v+;[a%
try{ K&X'^|en
URL url = new URL(siteInfoBean.getSSiteURL()); o?b%L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AH7k|6ku<*
httpConnection.setRequestProperty("User-Agent","NetFox"); 0)/214^&
)8<X6
c8'8DM
int responseCode=httpConnection.getResponseCode(); I#Bz UF
if(responseCode>=400) g@U#Y#b@"
{ o}%fs *
processErrorCode(responseCode); `j(+Y
return -2; //-2 represent access is error T2->
} $?s^HKF~
s{IoL_PJP
aQG#bh [
String sHeader; jPs+i
B@=Yj_s
kDz.{Ih
for(int i=1;;i++) UP`q6]P
{ $YC~02{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $e_ps~{7$
//Utility.log(in.readLine()); Wp]EaYt2D
sHeader=httpConnection.getHeaderFieldKey(i); g|zK%tR_P
if(sHeader!=null) ]S:@=9JB'
{ H|!s.
if(sHeader.equals("Content-Length")) v]J# SlF
{ 7 dzE"m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \%C[l
break; yjr@v!o
} KF'M4P
} NV gLq@F
else ~mp$P+M(%p
break; t,+S~Cj|
} iWCV(!
} Z-<u?f8{*
catch(IOException e){e.printStackTrace ();} joA+
catch(Exception e){e.printStackTrace ();} }ot _k-
O`u!P\
Om^/tp\
Utility.log(nFileLength); O7\s1 V;
(LfVa`<1
7X|r';"?i
return nFileLength; {#%xq]r_
} Y;w]u_
}-vBRY
y(dS1.5F
//保存下载信息（文件指针位置） Z~uKT n
private void write_nPos() br;G5^j3?
{ ]M2<I#hF.
try{ ./ :86@O
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]/bE${W*]
output.writeInt(nStartPos.length); i#lo?\PO>
for(int i=0;i<nStartPos.length;i++) ypd?mw&1}
{ 4yA`);r62
// output.writeLong(nPos); 6+5Catsn
output.writeLong(fileSplitterFetch.nStartPos); Z]Y4NO;
output.writeLong(fileSplitterFetch.nEndPos); ]Rye AJ3
} AAW7@\q.
output.close(); *p3P\ H^5
} c{Kl?0#[
catch(IOException e){e.printStackTrace ();} nADd,|xD3
catch(Exception e){e.printStackTrace ();} LC{hoq\
} mig3.is
(HI%C@e9
b8>9mKs
//读取保存的下载信息（文件指针位置） !_) ^bRd
private void read_nPos() (Pd>*G\
{ qJA.+q.e$e
try{ f 99PwE(=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uE j6A
int nCount = input.readInt(); GU3/s&9
nStartPos = new long[nCount]; 0f^.zt{T
nEndPos = new long[nCount]; qfu2}qUX~%
for(int i=0;i<nStartPos.length;i++) \2pFFVT
{ At(9)6n8
nStartPos = input.readLong(); 9C;Y5E~'L
nEndPos = input.readLong(); a1SOC=.M;
} 05B+WJ1
input.close(); ^kvH/Y&
} =on!&M
catch(IOException e){e.printStackTrace ();} qD*\}b]9I
catch(Exception e){e.printStackTrace ();} 3\r@f_p
} 1omvE9 %zM
M7R&J'SAY
suFOc
private void processErrorCode(int nErrorCode) (Fzh1#
{ Ki/5xK=s
System.err.println("Error Code : " + nErrorCode); Xp6*Y1Y
} k_<{j0z.
K9Xd? ]a
oxQID
//停止文件下载 b0Ov+ )7#
public void siteStop() rJZs 5g`
{ Treh{s
bStop = true; :ZS8Zm"
for(int i=0;i<nStartPos.length;i++) o?K|[gNi
fileSplitterFetch.splitterStop(); ~e77w\Q0
v\(m"|4(i
"P5bYq%0v
} ]H#Rm#q
} q'F_j"
//负责部分文件的抓取 Xm:=jQn
**FileSplitterFetch.java $;uWj|
*/ *rcuhw"^b#
package NetFox; 0j!ke1C&C
b2X'AHK S
?ZHE8
import java.io.*; =j+oKGkoCa
import java.net.*; x56 F
Cxk$"_
(_qBsng:
public class FileSplitterFetch extends Thread { 207O["Y
7s8<FyFsjd
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String sURL; //File URL w}W@M,.^
long nStartPos; //File Snippet Start Position y|;8:b32
long nEndPos; //File Snippet End Position FK@ f'
int nThreadID; //Thread's ID mE^tzyh
boolean bDownOver = false; //Downing is over O<dZA=Oez
boolean bStop = false; //Stop identical u@bOEcxK
FileAccessI fileAccessI = null; //File Access interface o%+A<Ri
Z0"&
|c oEBFG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d@6:|auO
{ 5G'&9{oB
this.sURL = sURL; c[h'`KXJf-
this.nStartPos = nStart; t}XB|h
this.nEndPos = nEnd; #'4<> G]
nThreadID = id; WE5"A| =
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^%oG8z,L
} zY+t,2z
WAwfL?
hnsa)@
public void run() F9k I'<Q
{ jTd4H)
while(nStartPos < nEndPos && !bStop) mo|PrLV
{ 9B+ zJ Vte
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uP%axys
try{ f/0v' Jt
URL url = new URL(sURL); us\%BxxI9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S2'`|uI
httpConnection.setRequestProperty("User-Agent","NetFox"); m~Y'$3w
String sProperty = "bytes="+nStartPos+"-"; lPRdwg-
httpConnection.setRequestProperty("RANGE",sProperty); vbRrk($`
Utility.log(sProperty); x2j/8]'o
vh|Tb5W<
Jt-XmGULB
InputStream input = httpConnection.getInputStream(); (#j2P0B
//logResponseHead(httpConnection); <\1}@?NGC
_.d}lK3$2
jiA5oX^g
byte[] b = new byte[1024]; >/TB_ykb
int nRead; "pSH!0Ap\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HA^jk%53
{ E8T"{ R80
nStartPos += fileAccessI.write(b,0,nRead); |5oKq'(b
//if(nThreadID == 1) {yvb$ND|j{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y!++CMzU
} Y<p zy8z
pu/m8
F=oHl@
Utility.log("Thread " + nThreadID + " is over!"); [2GXAvXsT
bDownOver = true; T!u'V'Ei2
//nPos = fileAccessI.write (b,0,nRead); :DZLjC
} ,}9f(`
catch(Exception e){e.printStackTrace ();} js:C mnI
} do:QH.q8)
} CS~=Z>6EjA
uY&=eQ_Cb
Cz'xGW{
//打印回应的头信息 ]j& FbP)3
public void logResponseHead(HttpURLConnection con) +M44XhT
{ ftYR,!&
for(int i=1;;i++) b@=zrhQ
{ RH!SW2o<
String header=con.getHeaderFieldKey(i); H|PrsGW
if(header!=null) 'R^iKNPs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^G}# jg.
Utility.log(header+" : "+con.getHeaderField(header)); >Hdjsu5{N
else vP3K7En
break; uz*d^gr}
} E4Y"X
} -'80>[}q/
7<h.KZPc
ixOEdQ
public void splitterStop() Y3-]+y%l
{ q{a#HnZo"
bStop = true; e{,!|LhpQ
} yJnPD/i
]UK`?J=t2g
:&Qb>PH[
} 'n~fR]h}
sS C?io
OI~}e,[2z
/* ]}BB/KQy^
**FileAccess.java CfQf7-
*//文件访问(定位，写) fH-NU-"
package NetFox; j h; 9 [
import java.io.*; iPMB$SdfO
,+~2&>wj
0;}Aj8Fle
public class FileAccessI implements Serializable{ j._G7z/LJ
;5<P|:^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0r1g$mKb
RandomAccessFile oSavedFile; -Bj.hx*
long nPos; f.@Xjf
BRe{1i 6
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public FileAccessI() throws IOException >OT\~C
{ LRWOBD
this("",0); 5!<o-{J[(=
} #-,g&)`]
%>i@F=O2<
zCBplb
public FileAccessI(String sName,long nPos) throws IOException /v5qyR7an
{ rxQ<4
oSavedFile = new RandomAccessFile(sName,"rw"); ICk(z~D~
this.nPos = nPos; WS5A Y @(~
oSavedFile.seek(nPos); -<6v:Z
} ]K7`-p~T
x7f:F.
!;i*\ a
public synchronized int write(byte[] b,int nStart,int nLen) 5!~!j "q
{ S0F@#mSQ?
int n = -1; fVYiwE=F
try{ LaDY`u0G%
oSavedFile.write(b,nStart,nLen); 9J?W '8s5
n = nLen; -)X{n?i
} w5,6$#
catch(IOException e) RYt6=R+f
{ J=):+F=
e.printStackTrace (); 5lO^;.cS,
} %8 qSv%_
t')h{2&&!2
`Z:3`7c
return n; ;J'OakeVO
} c)03Ms4 D
_D-5}a"
3g;T?E
} YX_vv!-]
A]j}'
u)7*Rj^
/* Hr6wgYPi
**SiteInfoBean.java H"O$&
*/ '|&,E#`
package NetFox; 8hZwQ[hr
Q? qjWZY
ms7SoYbSu
public class SiteInfoBean { IQIbz{bMx
$Buf#8)F*
%bXsGPB
private String sSiteURL; //Site's URL ^T{8uJ'kn
private String sFilePath; //Saved File's Path ?NlSeh
private String sFileName; //Saved File's Name :Dayv6g
private int nSplitter; //Count of Splited Downloading File Ih()/(
Yq J]7V\
[.a;L">
public SiteInfoBean() Mm.Ql
{//nSplitter的缺省值为5 %]#VdS|N
//default value of nSplitter is 5 AeaPK
this("","","",5); kQ~ %=pn
} |#V(p^
ge$LIsE8
(`pNXQ0n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9\>sDSCx
{ Jh?z=JY
sSiteURL= sURL; QF.3c6O@
sFilePath = sPath; kxh 5}eB
sFileName = sName; /~*Cp9F"]
this.nSplitter = nSpiltter; /1[gn8V691
0V3gKd7
EI\v
} g#qNHR
P_}/#N{C
7b46t2W<
public String getSSiteURL() y:,9I`aW
{ 8?1o<8hV
return sSiteURL; Mn@$;\:
} xg} ug[
<BPRV> 0X
4>YU8/Rw
public void setSSiteURL(String value) Oqmg;\pm
{ 61Bhm:O5W
sSiteURL = value; d&u7]<yDA
} ZBJ3VK
-w~(3(
Q&PB]D{
public String getSFilePath() MRs,l'
{ sPy2/7Wqd
return sFilePath; xs%LRF#u
} U` hfvTi
8R}K?+]
@!<d0_dnC
public void setSFilePath(String value) 72,"Cj
{ +T2HE\
sFilePath = value; Qci$YTwl>
} jTfi@5aPY
o%`npi1y
ik5|,#}m&
public String getSFileName() LwOJ|jA(,
{ > :Ze4}(
return sFileName; i3PKqlp.
} 2tf6GX:
xnbsg!`;7W
N_G4_12(
public void setSFileName(String value) e:OyjG5_
{ 6/6Rah!
sFileName = value; *b"CPg/\
} ;'HF'Z
"OL~ul5
-CD\+d "
public int getNSplitter() <uD qYT$6
{ =VSkl;(O
return nSplitter; 2]2H++
} C),7- ?
/K|:9Q$K6
FZXyfZw!|
public void setNSplitter(int nCount) kXwi{P3D$
{ {155b0
nSplitter = nCount; .GCR!V
} ?4G(N=/&
} JMlV@t7y<
w!`Umll2
cJ/]+|PQ
/* //.>>-~1m
**Utility.java U-EhPAB@
*/ "K?Q
package NetFox; ?z=\Ye5x
U=cWmH
QU/3X 1W
public class Utility { tg85:
NfwYDY
wqy^8N[K]
public Utility() %{C)1*M7
{ >SDpuG&>
f^9&WT
PZ,z15PG]
} >uy%-aXiVa
P`TIaP9%E
//线程睡眠 +xj "hX>3
public static void sleep(int nSecond) IgM v =^U
{ yC !/PQ"
try{ %idk@~HCg
Thread.sleep(nSecond); 0@pu@DP~
} hz\WZ^
catch(Exception e) l67KJ
{ i-lKdpv
e.printStackTrace (); KDey(DN:
} "8(U\KaX
} eH <Jng
vM4<d>
//日志 .Yx_:h=u
public static void log(String sMsg) 4D"4zp7
{ 6)[<)?A.[
System.err.println(sMsg); #3MKH8k&~
} {TAw)!R~
\%5MAQS
r]LCvsVa
public static void log(int sMsg) %8FN0
{ ut&/\k=N
System.err.println(sMsg); 6 h'&6
} ;7rv
} 6G_<2bO
u7=T(4a
YaL]>.;Z:"
/* k+1gQru{d
**TestMethod.java t;47(U
*/ #C*&R>IvY
package NetFox; ]ii+S"U3
u) *Kws
WRpyr
public class TestMethod { ,X/-
+K{LQsR]
j*zD0I]
public TestMethod() C6QbBo
{ ///xx/weblogic60b2_win.exe T PYDs+U
try{ T~k)uQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #H5=a6E+q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ty+I8e]{
SiteFileFetch fileFetch = new SiteFileFetch(bean); )`?%]D
fileFetch.start(); V3.t;.@
} zxKCVRJ
catch(Exception e){e.printStackTrace ();} %}b8aG+
LM.`cb;?G
Zdn!qyR`
} h-mTj3p-K
O4Dr ]Xc]
~<ri97)
public static void main(String[] args) PW)aLycPK
{ =~|:t&v=c
new TestMethod(); {THqz$KN
} |y1;&<
} GAl+Zg##
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