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)); JT "B>y>
} Dq36p${\W
for(int i=0;i<nEndPos.length-1;i++) >ELlnE8
{ }"|"Q7H
nEndPos = nStartPos[i+1]; 6'kS_Zu{<
} c1$ngH0
nEndPos[nEndPos.length-1] = nFileLength; u5 {JQO
} >H(i^z/c
} nB%;S
D?C)BcN
aO@7O*
//启动子线程 tp6M=MC%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eh4gQ^l
for(int i=0;i<nStartPos.length;i++) J8M$k/"X
{ Zm"{Viv]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ndjx|s)E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5Xl/L
nStartPos,nEndPos,i); 'fcMuBc+4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "Fy7K#n
fileSplitterFetch.start(); 0O\SU"bP
} {r>.G7P6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {%VV\qaC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pl5P2&k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f6_];]yP
nEndPos = " + nFileLength); ;<$H)`*
// fileSplitterFetch[nPos.length-1].start(); s[K^9wz
yz-,)GB6
&ISb~5
//等待子线程结束 :Xn7Ha[f
//int count = 0; :l2g#* c
//是否结束while循环 M t*6}Cl
boolean breakWhile = false; _*IPk
qw7@(R'"
DUL4noq{
while(!bStop) Kx.X7R
{ MZpK~c1`
write_nPos(); aM@z^<Ub
Utility.sleep(500); Q\GDrdA
breakWhile = true; K,6b3kk
&K43x&mFF
uQ=^~K:Z~
for(int i=0;i<nStartPos.length;i++) )J_\tv
{ ew;ur?
if(!fileSplitterFetch.bDownOver) ]J* ,g,
{ -DN8Yb
breakWhile = false; cFN'bftH4
break; EyI}{6~F
} 4-kZJ\]
} !IC-)C,q
if(breakWhile) v?0r`<Mn
break; &-czStQ
kdxz!
WYIQE$SEv
//count++; /erN;Oo%<
//if(count>4) Dy]I8_
// siteStop(); >6~k9>nDb<
} <W`#gn0b6
4\pWB90V
RP2_l$
System.err.println("文件下载结束！"); WpS1a440
} (faK+z,*6R
catch(Exception e){e.printStackTrace ();} YXU|h
} $B#6tk~u
b1gaj"]
\.f}W_OF
//获得文件长度 G/d4f?RU
public long getFileSize() 7_wJpTz
{ T"p(]@Ng
int nFileLength = -1; ?\U!huu
try{ yJsH=5A
URL url = new URL(siteInfoBean.getSSiteURL()); &f>eQS=(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gy,u^lkk:
httpConnection.setRequestProperty("User-Agent","NetFox"); j7MO'RX`&
9D 0dg(
-UZ@G~K
int responseCode=httpConnection.getResponseCode(); ]&ixhW
if(responseCode>=400) 4D$;KokZ
{ g|Y] wd
processErrorCode(responseCode); tM,%^){p$
return -2; //-2 represent access is error 'JdkUhq1V
} 9Ew7A(BG_3
B-*E:O0y
ewuXpv%vwW
String sHeader; ="%W2
!@I}mQ ~
ExSO|g]%
for(int i=1;;i++) Q \]Xm>
{ 5tv<8~:K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uNHdpni
//Utility.log(in.readLine()); TZ;p0^(
sHeader=httpConnection.getHeaderFieldKey(i); e8h,,:l3j
if(sHeader!=null) '~ 4pl0TWc
{ T"T;`y@(
if(sHeader.equals("Content-Length")) DY{cQb
{ e,k2vp!<&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KtB!"yy#
break; Z?NEO>h7
} )9B:wc"
} G~wFnl%
else HPQ/~0$
break; %d m-?`
} G){g
} h{}mBQl
catch(IOException e){e.printStackTrace ();} [pg}S#A
catch(Exception e){e.printStackTrace ();} '4OcZ/oI
#fs|BV !
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Utility.log(nFileLength); IN7<@OS7
xU S]P)R
9p@C4oen
return nFileLength; ?/M_~e.P
} V8-h%|$p3W
0IT@V5Gdj
BHj\G7,S
//保存下载信息（文件指针位置） JI|6B
private void write_nPos() ukuo:P<a
{ W3&tJ8*3
try{ ~%ozgzr^
output = new DataOutputStream(new FileOutputStream(tmpFile)); U>S`k6
output.writeInt(nStartPos.length); "R9Yb,tIN
for(int i=0;i<nStartPos.length;i++) Qn:kz*:
{ PzZZ>7_6S
// output.writeLong(nPos); XM|%^ry
output.writeLong(fileSplitterFetch.nStartPos); i3mAfDF
output.writeLong(fileSplitterFetch.nEndPos); b-@\R\T
} 7S$&S;
output.close(); /^#G0f*N
} |%D%0TR&Q
catch(IOException e){e.printStackTrace ();} Zg:gY"^
catch(Exception e){e.printStackTrace ();} 7m9"8
} O'NW Ebl/
c 5`US
68R1AqU_
//读取保存的下载信息（文件指针位置） H]31l~@]
private void read_nPos() IeF keE
{ ~VTs:h
try{ Y7U&Q:5'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1;| LI?
int nCount = input.readInt(); GZ}/leR
nStartPos = new long[nCount]; BRbV7&
nEndPos = new long[nCount]; ohc1 ~?3b
for(int i=0;i<nStartPos.length;i++) XidxNPz0^
{ #T~&]|{,
nStartPos = input.readLong(); F9XT lA
nEndPos = input.readLong(); !:fv>FEI9
} Vf-5&S&9
input.close(); Omag)U)IPh
} cs_}&!c{
catch(IOException e){e.printStackTrace ();} Zv qn%K],
catch(Exception e){e.printStackTrace ();} y/_wx(2
} vt]F U<
oP,9#FC|(
t7F.[uWD
private void processErrorCode(int nErrorCode) `_ (~ Ud
{ > %*B`oqo
System.err.println("Error Code : " + nErrorCode); VY'Q|[
} ; !$m1
dEp/dd~(&
?RD *1
//停止文件下载 . p^xS6e{
public void siteStop() +=cam/A
{ We`'>'W0
bStop = true; IS]{}Y\3H
for(int i=0;i<nStartPos.length;i++) gbOCR1PBg
fileSplitterFetch.splitterStop(); L2-^!'
mog9jw
(TSqc5^H
} ~!+h?[miV
} V`fL%du,3
//负责部分文件的抓取 5)+F(
**FileSplitterFetch.java #iis/6"
*/ m/USC'U%
package NetFox; A%ywj'|z
*,#q'!Hq
S2=%x.
import java.io.*; 0^_MN~s(X
import java.net.*; 3;$bS<>
PDw{R]V+
d,'!.#e
public class FileSplitterFetch extends Thread { ]1fZupM^6
<fM>Yi5
9Z!lmfnJ
String sURL; //File URL ^Gz{6@TY5
long nStartPos; //File Snippet Start Position &v#`t~
long nEndPos; //File Snippet End Position )&Z>@S^
int nThreadID; //Thread's ID K&pM o.
boolean bDownOver = false; //Downing is over G%w_CMfH
boolean bStop = false; //Stop identical izt^Wi|
FileAccessI fileAccessI = null; //File Access interface ZTf_#eS$
%"7WXOv&z
dl[ob,aCK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException boQ)fV"
{ rB]W,8~%
this.sURL = sURL; *Wyl2op6
this.nStartPos = nStart; 0#|7U_n
this.nEndPos = nEnd; yMIT(
nThreadID = id; =Nl5{qYz^&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kEK[\f VE
} ."JzDs
:|XCnK0
`*9EKj
public void run() |Is'-g!
{ Ysk,w,K
while(nStartPos < nEndPos && !bStop) a%[q |oyR
{ )|T`17-
p~>_T7ze
{'(ej5,6
try{ ATO 5
URL url = new URL(sURL); Z>{*ISvpq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b:x7)$(
httpConnection.setRequestProperty("User-Agent","NetFox"); }|He?[TR
String sProperty = "bytes="+nStartPos+"-"; ib50LCm
httpConnection.setRequestProperty("RANGE",sProperty); <kc]L x
Utility.log(sProperty); 0_V*B[V
75(W(V(q
iwz` x
InputStream input = httpConnection.getInputStream(); M]0^ind
//logResponseHead(httpConnection); }=pOiILvD
QV)}3pW
7x+=7,BZd
byte[] b = new byte[1024]; FuMq|S
int nRead; r } 7:#XQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hs<n^fyf
{ e 2*F;.)
nStartPos += fileAccessI.write(b,0,nRead); LV=^jsQ5
//if(nThreadID == 1) ^?Vq L\V5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DB Xm
} ;E2kT GT
XZBj=2~-3
j&llrN
Utility.log("Thread " + nThreadID + " is over!"); AFtCqq#[
bDownOver = true; El1:?4;
//nPos = fileAccessI.write (b,0,nRead); zPE#[\O21B
} %Ht^yemQ
catch(Exception e){e.printStackTrace ();} ;zm ks]
} ):}Fu
} gL,"ef+nM
p[;8
b.6ZfB,+G
//打印回应的头信息 T:@7S
public void logResponseHead(HttpURLConnection con) Bb_}YU2#
{ Uk"Y/Ddm
for(int i=1;;i++) 6 <r2*`
{ YZ{jP?x
String header=con.getHeaderFieldKey(i); :>ZzP:QD
if(header!=null) zK /f$}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^OjvL6A/p
Utility.log(header+" : "+con.getHeaderField(header)); %d-`71|lG^
else :D^Y?
break; MyM+C}
} 7n<#y;wo
} }RDb1~6C
Z3I L8
xK=J.>h3
public void splitterStop() IPkA7VhFF
{ X#Ak'%J
bStop = true; S^)WYF5
} j$%yw4dsj
)j(fWshP
B{N=0 cSi
} haik
w+3>DEfz
u,!4vKx
/* T!&jFy*W
**FileAccess.java @?j@yRe
*//文件访问(定位，写) )MMhlcNC
package NetFox; <Q\H
import java.io.*; g!.Ut:8L9
sOjF?bCdO
O'@m4@L
public class FileAccessI implements Serializable{ 0\ZaMu #
wFn@\3%l`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 widI s[ )
RandomAccessFile oSavedFile; >9(7h&[Y
long nPos; &l?N:(r
hq]xmM?&
a$laRtId7
public FileAccessI() throws IOException 3a/[."W u
{ N!.kq4$.
this("",0); rSzQUn<
} jaL$LJV
X9z:D>
%e(9-M4*
public FileAccessI(String sName,long nPos) throws IOException P7cge
{ % i%ew4
oSavedFile = new RandomAccessFile(sName,"rw"); %f>X-*}NI-
this.nPos = nPos; 2z[r@}3
oSavedFile.seek(nPos); p"g1V7B
} D8q3TyCj%
)#)nBM2\
;K>{_kf
public synchronized int write(byte[] b,int nStart,int nLen) kT>r<`rt
{ e!.7no
int n = -1; rL.<Z@-
try{ @*bvMEE
oSavedFile.write(b,nStart,nLen); :QxL 9&"
n = nLen; +p8qsT#7
} T-hU+(+hg
catch(IOException e) 9*7Hoi4Ji
{ M" xZz
e.printStackTrace (); JTSq{NN
} v&k>0lV,^
l7!U),x%/U
)PsN_ 42~
return n; XKpL4]{&q4
} m]{<Ux
)RpqZe/h4
y|FBYcn#F
} v@F|O8t:s
E_ o{c5N
%kFTnXHK
/* Qx9>,e6+
**SiteInfoBean.java +3NlkN#
*/ ./7&_9|<
package NetFox; }<6oFUZ
T][-'0!
"$`wk
public class SiteInfoBean { D2>hMc
4.,KEt'H
<K=@-4/Bp
private String sSiteURL; //Site's URL [K"U_b}w
private String sFilePath; //Saved File's Path e6tH/`Uln
private String sFileName; //Saved File's Name N*_/@qM> a
private int nSplitter; //Count of Splited Downloading File z Y$X|=f
HA$^ *qn
zz7Y/653
public SiteInfoBean() 4iYgs-,
{//nSplitter的缺省值为5 |@T5$Xg]5
//default value of nSplitter is 5 o(B<!ji~'
this("","","",5); J=f:\]@Oy
} v_?s1+w
{bAWc.
NB|RZf9M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0A) Vtj$
{ Yio>ft&g]
sSiteURL= sURL; xI/{)I1f
sFilePath = sPath; zbF:R[)
sFileName = sName; m;;0 Cl
this.nSplitter = nSpiltter; 4jC4X*
>%PL_<Vbv
[dSDg2]
} [4K9|/J
7yq7a[Ra
LUe>)eqw
public String getSSiteURL() ~!a~C~_
{ 2b6? 9FX*
return sSiteURL; ``2QOu 1
} _IQU<Za
fPh}l
F20wf1^
public void setSSiteURL(String value) Q:-%3)g<<
{ Dz"u8 f
sSiteURL = value; ? 6yF{!F*
} PV,kYM6
yV 9]_k
Z@>=&
public String getSFilePath() 7- *(a
{ I]uOMWZs
return sFilePath; (<d&BV-"
} 'S%} ?#J
. Ce&9l
}skRlC
public void setSFilePath(String value) m>Yo9/XpZ
{ 7dM6;`V^
sFilePath = value; 1_33;gP
} #Lhj0M;a
LK
?$)x$nS`
public String getSFileName() Tc'{i#%9j
{ #f|NM7
return sFileName; 'XZI{q2i
} E1U4v&P
gW6G+
6oTbn{=UUq
public void setSFileName(String value) %h/#^esi
{ ^\7 x5gO
sFileName = value; 2$SofG6D}
} ]RJb;
Oet#wp/I
1Rb XM n
public int getNSplitter() !yV,|)y5F
{ Th&Wq
return nSplitter; DJD]aI
} V#-qKV
_v~D{H&}
HX /GLnY/X
public void setNSplitter(int nCount) NSxPN:
{ $tt0D?$4
nSplitter = nCount; oqd N5+xt
} M3jv aI
} E1{:z"
H/p-YtY
3j=%De
/* \CJx=[3(
**Utility.java bCE7hutl
*/ M0Kh>u
package NetFox; xtIehr0{$I
8XH|T^5
8f{}ce'E*
public class Utility { quCWc2pXX
n ]6 0
wEHAkc)Q
public Utility() UgD'Bi
{ ['}^;Y?*o
qUoMg%Z%l
\AtwO
} Kl46CZs#8
HM$`z"p5jg
//线程睡眠 MWn L#!
public static void sleep(int nSecond) mSk :7ozZ
{ v]`A_)[
try{ \:_.N8"
Thread.sleep(nSecond); Y#SmZ*zok
} ?2;n=&ZM
catch(Exception e) g~^{-6Vg
{ ot>EnHfV
e.printStackTrace (); \yX !P1
} U$/Hp#~X
} +2au ;^N
Hh/ -^G
//日志 AHMV@o`V
public static void log(String sMsg) VM\Z<}C
{ LL$,<q%(P
System.err.println(sMsg); PgG |7='
} [b k&Nd[
^ ]6 80h
~&[P` Z$
public static void log(int sMsg) n?P 5pJ
{ $?/Xk%d+
System.err.println(sMsg); @)2V"FE4i
} uuUVE/^V'
} ev: !,}]w
,~j$rs`Z
Q~w G(0'8
/* <v7KE*#
**TestMethod.java q@MjeGs%
*/ .e _D3Xp<
package NetFox; 4QKE{0NE
,m?UFRi
?_Dnfa_
public class TestMethod { d-N"mI-
gh #w%g1g
y~A7pzBZ=
public TestMethod() l-^XW?CfL
{ ///xx/weblogic60b2_win.exe H;t8(-F@'
try{ $vGEY7,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); da?th
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o4[2`mT
SiteFileFetch fileFetch = new SiteFileFetch(bean); 18/@:u{
fileFetch.start(); M(h H#_$
} ;\*Od?1
catch(Exception e){e.printStackTrace ();} ,@>rubUz
f`9rTc
^9*|_\3N
} w[A3;]la
#c)Ou!Ldb
QV H'06"{
public static void main(String[] args) s-N?Tzi
{ 9;v"bcQ
new TestMethod(); V+a%,sI
} *r?51*J
} + $a:X
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