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)); zV]0S o
} pP#?|
for(int i=0;i<nEndPos.length-1;i++) tXx9N_/
{ LuVj9+1 S
nEndPos = nStartPos[i+1]; a5iMCmL+
} m:t$&
nEndPos[nEndPos.length-1] = nFileLength; 1Sy#*
} ,rKN/{M!
} DCm;dh
Z7v~;JzC#
}y1M0^M-$
//启动子线程 'coqm8V[%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e0TnA N
for(int i=0;i<nStartPos.length;i++) 2a^(8A`7W
{ VXa]L4jJ9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1#V0g Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B.|vmq,u
nStartPos,nEndPos,i); d3\8BKp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I.>LG
fileSplitterFetch.start(); 1L0ku@%t9Y
} z(xvt>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8P 8"dN[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $#!~K2$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YANEdH`d
nEndPos = " + nFileLength); +38t82%YWo
// fileSplitterFetch[nPos.length-1].start(); VYwaU^
s-*XAnot
R8KL4g-d
//等待子线程结束 +%yh@X6
//int count = 0; ps]6,@uyB
//是否结束while循环 3B0%:Jj
boolean breakWhile = false; ;# {x_>M
g^idS:GtX5
LCG<
while(!bStop) _YY)-H
{ }LRAe3N%8
write_nPos(); I4*N
Utility.sleep(500); ^Iz.O
breakWhile = true; }XUHP%
?:ZH%R_`a
yDKX,
for(int i=0;i<nStartPos.length;i++) L=$P
{ fkYQ3d,`
if(!fileSplitterFetch.bDownOver) OV[-m;h|
{ Zwcb5\Q
breakWhile = false; 0K!9MDT}*
break; yP-Dj ,
} I}:/v$btM
} *n47.(a2i
if(breakWhile) 97g\nq<
break; 'fB`e]_
1vThb
&qr7yyY
//count++; oH;Y}h
//if(count>4) #\jPBLc
// siteStop(); H0Tt(:.&
} T&c[m!}X|t
lyV]-w
dug RO[
System.err.println("文件下载结束！"); PyoLk
} 4e:hKv,+4
catch(Exception e){e.printStackTrace ();} qUo(hbp
} @f$P*_G
A;g[G>J
pSAXp#g
//获得文件长度 >8VJ!Kg4
public long getFileSize() Ua:EI!`
{ t!~mbx+
int nFileLength = -1; cr!I"kTgD
try{ QEVjXJOt0
URL url = new URL(siteInfoBean.getSSiteURL()); R =jK3yfw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AkF1Hj
httpConnection.setRequestProperty("User-Agent","NetFox"); %8ul}}d9
|`|b&Rhu
;R67a V,
int responseCode=httpConnection.getResponseCode(); 0QPipuP
if(responseCode>=400) ed{9UJWh
{ XH. _Z
processErrorCode(responseCode); HqbTJ!a
return -2; //-2 represent access is error LP87X-qkjW
} Q.N^1?(>k
WgIVhj
V=c&QPP
String sHeader; f="}.
;9^B# aTM
Y}Ov`ZM!r
for(int i=1;;i++) &8(2U-
{ N5s_o0K4TU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G6 GXC`^+
//Utility.log(in.readLine()); c" l~=1Dr
sHeader=httpConnection.getHeaderFieldKey(i); OS!47Z /q
if(sHeader!=null) ]/a?:24[
{ ^cY5!W.q8
if(sHeader.equals("Content-Length")) DJ\lvT#j
{ ~(^[TuJC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ro1l:P)C`
break; [)a,rrhj
} o;O_N^_W
} 9uq| VU5
else A_g'9
break; -uh/W=Q1R
} bXJE 2N
} MF1u8Yl:0
catch(IOException e){e.printStackTrace ();} WcdU fv(>
catch(Exception e){e.printStackTrace ();} [Nq4<NK
H95VU"
hIdGQKr>V
Utility.log(nFileLength); 9KP+
1rN&Y,61\
O`2%@%?I
return nFileLength; 7#RW4ZM
} Ghj6&K%b0
,^'Y7"
KLxg
//保存下载信息（文件指针位置） \UiuJ+
private void write_nPos() H: U_k68
{ "XH]B
try{ TEYbB=.
output = new DataOutputStream(new FileOutputStream(tmpFile)); 86I".R$d
output.writeInt(nStartPos.length); > 4^U=T#
for(int i=0;i<nStartPos.length;i++) xv)7-jlx
{ !is8`8F8
// output.writeLong(nPos); ZpwB"%e$
output.writeLong(fileSplitterFetch.nStartPos); G1D(-X4ALZ
output.writeLong(fileSplitterFetch.nEndPos); ?6[>HX;
} s2tEyR+gW
output.close(); 8g$ 8]'M^T
} V9MA)If>
catch(IOException e){e.printStackTrace ();} ^awl-CG
catch(Exception e){e.printStackTrace ();} f5O*Njl
} 0!^{V:DtQ
20J:_+=]
"\BLi C
//读取保存的下载信息（文件指针位置） 4iKT
private void read_nPos() co;2s-X
{ \=QG6&_
try{ h rZ\ O?j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qdtfi1_Y1
int nCount = input.readInt(); ";GLX%C!{@
nStartPos = new long[nCount]; 9eV@v
nEndPos = new long[nCount]; =7jkW (Q
for(int i=0;i<nStartPos.length;i++) =]D##R
{ I*0W\Qz@
nStartPos = input.readLong(); %Jw;c`JM
nEndPos = input.readLong(); ;DRJL
} <=0_[M
input.close(); ?1[go+56X
} \^_F>M
catch(IOException e){e.printStackTrace ();} 2\7]EW
catch(Exception e){e.printStackTrace ();} Gjzhgz--
} 7igrRU#1%
{yJ{DU?%Y
I5-/KVWb
private void processErrorCode(int nErrorCode) C[[z3tn
{ ?.4u'Dkn=
System.err.println("Error Code : " + nErrorCode); O/GD[9$i
} #$A6s~`B
wi&m(f(~
}g`A*y;t
//停止文件下载 JiRW|+`pe
public void siteStop() {Xl 5F.q
{ lD{9o2
bStop = true; )`L!eN
for(int i=0;i<nStartPos.length;i++) Z3I<
fileSplitterFetch.splitterStop(); &3AGj,
/at#[Pw~01
H >RGX#|
} JNZKzyJ9K
} R^K<u#>K
//负责部分文件的抓取 aZmSCi:&'
**FileSplitterFetch.java ov?>ALRg
*/ 7=JiL=
package NetFox; :FK(*BUh
V+E2nJ
ost~<4~
import java.io.*; |vGz 1jLV
import java.net.*; D F0~A
2#sE\D
p[W8XX
public class FileSplitterFetch extends Thread { 1N2:4|woe
d`v]+HK
ty(F;M(
String sURL; //File URL br0gB3r
long nStartPos; //File Snippet Start Position {lqnn n3
long nEndPos; //File Snippet End Position \b' <q
int nThreadID; //Thread's ID bZ0r/f,n$
boolean bDownOver = false; //Downing is over c.NAUe_3
boolean bStop = false; //Stop identical '!Q[+@$
FileAccessI fileAccessI = null; //File Access interface 5<&<61[A
8pPAEf
qG~O]($
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c1Dhx,]ad
{ 1z*]MYU
this.sURL = sURL; 1z{AzpMZ
this.nStartPos = nStart; )82x)c<e
this.nEndPos = nEnd; n|{x\@VeF
nThreadID = id; |3vQmd !2}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 * \f(E#wa
} ;o#dmG
.O~)zMx
(3W<yAM+
public void run() [ UQzCqV
{ *-gS u
while(nStartPos < nEndPos && !bStop) +
{ tV%M2DxS
}`>u+iH#a
qA&N6`
try{ '%)7%O,2
URL url = new URL(sURL); cl^tX%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c6Wy1d^
httpConnection.setRequestProperty("User-Agent","NetFox"); N=-hXgX^
String sProperty = "bytes="+nStartPos+"-"; UiW(/L
httpConnection.setRequestProperty("RANGE",sProperty); Kh3*\xT
Utility.log(sProperty); ~,dj)x 3M
\9<aCJxN
;Q-(tGd
InputStream input = httpConnection.getInputStream(); (%\N-[yZ
//logResponseHead(httpConnection); eBG7]u,Q
O+c@B}[!
m &s0Ub
byte[] b = new byte[1024]; =XyK/$
int nRead; [O9(sWL'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )7:2v1Xr]
{ .}2^YOmd
nStartPos += fileAccessI.write(b,0,nRead); C$Ldz=d
//if(nThreadID == 1) |f.=Y~aY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Trm)7B*
} 9fyk7~V
Fj-mo>"
<?QY\wyikz
Utility.log("Thread " + nThreadID + " is over!"); hyFq>XFo
bDownOver = true; EcFYP"{U
//nPos = fileAccessI.write (b,0,nRead); V/<dHOfR\
} $d4eGL2S
catch(Exception e){e.printStackTrace ();} iiKFV>;t/
} MiAXbo#\
} ]#TL~u[
1u'x|Un
}G_ i+
//打印回应的头信息 @4_W}1W
public void logResponseHead(HttpURLConnection con) G23Mr9m5O
{ tk2B\}6
for(int i=1;;i++) zZGPA j
{ SO3WOR`3
String header=con.getHeaderFieldKey(i); {SJ=|L6
if(header!=null) +u:8#!X$RD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *~4w%U4T0
Utility.log(header+" : "+con.getHeaderField(header)); (Sv7^}j
else 2j*\n|"}{
break; 2-. g>'W
} a|
} NhS0D=v6
VNx}ADXu]
wnN@aO6g*
public void splitterStop() C<eeAWP3v
{ qdjRw#LS^q
bStop = true; |C\g3N-
} 3@\vU~=P:
?20y6c<
Y:ZI9JK?
} lTDF5.aE
g=:%j5?.e
G]=U=9ZI
/* 4cTJ$" v
**FileAccess.java 'w^1re=R
*//文件访问(定位，写) &B/cy<;y,
package NetFox; TJ ;4QL
import java.io.*; {y)s85:t
RHz'Dz>0
j+88J
public class FileAccessI implements Serializable{ )Tpc8Hr
tlA4oVII
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b'St14_
RandomAccessFile oSavedFile; P)tXU
long nPos; fI t:eKHr
Cx} Yp-
0@.$(Aqo(
public FileAccessI() throws IOException \"<&8
{ U3&*,xeU@H
this("",0); b^;19]/RW
} GKZn|<Y|{c
eN,s#/ip]
OHR9u
public FileAccessI(String sName,long nPos) throws IOException Q{0-pHr}
{ +[zrU`!@
oSavedFile = new RandomAccessFile(sName,"rw"); !3-mPG< ]
this.nPos = nPos; Z>Rd6o'
oSavedFile.seek(nPos); L`V6\Ix(I
} i/,G=yA
d_QHm;}Cx
T=ox;r
public synchronized int write(byte[] b,int nStart,int nLen) \V7Hi\)
{ lmz{,O
int n = -1; FJ!N)`[
try{ +`yDWN?7
oSavedFile.write(b,nStart,nLen); [t: =%&B
n = nLen; XaR(q2s
} Fu^^Jex
catch(IOException e) #D .H2'_}
{ 1Yz1/gFj
e.printStackTrace (); 7: J6 F
} 9 /t}S6b{
F<Z"W}I+6
Z@t).$
return n; &pZ]F=.r+
} &j2L-)
h}g _;k5R
}zlvs a+
} Q5Y4@
4Qz
+S<2d.&~
/* S;Lqx5Cd
**SiteInfoBean.java [ }jSx]
*/ WN?!(r<qA_
package NetFox; o5BOe1_Pw
$QNfy.6Tn
0 -=onX
public class SiteInfoBean { P7 (&*=V
gG*O&gQY
FOquQr1cF
private String sSiteURL; //Site's URL f2uog$Hk
private String sFilePath; //Saved File's Path ]^8:"Ky'
private String sFileName; //Saved File's Name +M-' K19
private int nSplitter; //Count of Splited Downloading File P-7!\[];te
RLw=y{%p

public SiteInfoBean() v~L} :
{//nSplitter的缺省值为5 8{4I6;e-
//default value of nSplitter is 5 xZGR<+t
this("","","",5); "h2;65@
} 6Ck?O/^
dK|MQ <
[0m'a\YE9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <saS2.4
{ )#xd]~<
sSiteURL= sURL; dm8veKW'l
sFilePath = sPath; :*0k:h6g
sFileName = sName; `vL R;D
this.nSplitter = nSpiltter; #y-OkGS ^
bsP:tFw>
0=t_a]+
} AH`tkPd
I"Ju3o?u
UF,T
public String getSSiteURL() dQ/Xs.8
{ K4,VSy1byI
return sSiteURL; i:qc2#O:J
} 0}Kl47}aD
{Y`0}
qW?^_
public void setSSiteURL(String value) ~AjbF(Ad
{ [EB2o.EsO
sSiteURL = value; 68;,hS*|6
} 4y>G6TD^
]L}<Y9)t
F]M3/M
public String getSFilePath() q'C'S#qqn
{ .zBSjh_=H
return sFilePath; #uuwzE*M_
} cMC1|3
+ #S]uC
d!Y,i!l!
public void setSFilePath(String value) <%qbU-
{ 6CY_8/:zL
sFilePath = value; <0JW[m
} kIU"-;5tP
`\e@O#,^yI
0ZkA.p
public String getSFileName() < g6 [mS
{ i+21tG$
return sFileName; ~Z.lvdA_5
} M"X/([G
5OpK~f5
k3S**&i!CR
public void setSFileName(String value) z4UeUVfZ}
{ D'uzH|z8
sFileName = value; e-UPu%'
} zLf^O%zN
-bZ^A~<O,
.$99/2[90
public int getNSplitter() s7a\L=#p(
{ %z.u % %
return nSplitter; 0DS<(
} Rqvm%sAi
O23f\pm&
QVzLf+R~
public void setNSplitter(int nCount) "z@qG]#5
{ l}:9)nXA{
nSplitter = nCount; X1tAV>k5'L
} ;v8,r#4
} j&Z:|WniK
D{a{$Pr
:tzCuK?e
/* hj0uv6t.c
**Utility.java a/>={mbKi
*/ lFI"U^xC
package NetFox; .i[Tp6'%,
o6B!ikz 8
sx*(JM}Be
public class Utility { s{$c8
@kI^6(.
Jw;J$ u!d
public Utility() < 8WS YZ
{ (_U&EX%
N @]*E
lyv9eM
} 1)%9h>F7
?$=N!>P#
//线程睡眠 )M'#l<9B
public static void sleep(int nSecond) o7]h;Zg5r
{ w;>]L.n
try{ Dve5Ml-
Thread.sleep(nSecond); #t3ju^ |?
} .\*\bvyCw
catch(Exception e) Lrr6z05FQ
{ 7&m*: J
e.printStackTrace (); >UR-37g{p
} "qQU ^FW
} aViJ?*
h1JG^w$ 5
//日志 @36^4E>h
public static void log(String sMsg) M7!&gFv8
{ (w"zI!
System.err.println(sMsg); d3^LalAp
} Ha4?I$'$
F}i rCi47c
!Y`nKC(=z
public static void log(int sMsg) 36&7J{MU
{ @: %}clZ
System.err.println(sMsg); tEBf2|<
} +>c)5Jih
} pEhWgCL
!Bu<6
|wVoJO!O}
/* UI>-5,X
**TestMethod.java %oC]Rpdu
*/ \=,+weGw@
package NetFox; B^{bXhDp
v|QFUa`
Tje =vI
public class TestMethod { H-7*)D
lE=Q(QUr
]#S.L'
public TestMethod() \p [!@d^
{ ///xx/weblogic60b2_win.exe _RY<-B
try{ LdVGFlcXi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X-~Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^'v6 ,*:4
SiteFileFetch fileFetch = new SiteFileFetch(bean); YgdoQBQ
fileFetch.start(); ,|xG2G6
} URJ"
catch(Exception e){e.printStackTrace ();} LNk 3=v2M
1pO ;aG1O
q:1 1XPP
} 6t/})Xv
E(]yjZ/
IO]Oo3
public static void main(String[] args) ckN/_ u3
{ %#ms`"H
new TestMethod(); /KlA7MH6
} .-c3f1i
} z9;vE7n!
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