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)); l$:?82{
} qmy3pnL
for(int i=0;i<nEndPos.length-1;i++) 4Pv Pp{Y
{ I?R?rW
nEndPos = nStartPos[i+1]; bnzIDsw!Q
} E7`Q=4@e
nEndPos[nEndPos.length-1] = nFileLength; goje4;
} gt \O
} !+o`,KTYp
96#aGh>
-\I".8"YE
//启动子线程 hVGK%HCz&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @9AK!I8f
for(int i=0;i<nStartPos.length;i++) Ljs4^vy<J
{ v!WkPvU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _C4N6YdU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |!6<L_31%
nStartPos,nEndPos,i); ZNUSHxA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fi8#r)G.
fileSplitterFetch.start(); T*1`MIkv
} (dnaT-M3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7*>(C*q=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;!:@3c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q]\GBRp
nEndPos = " + nFileLength); x%J.$o[<_
// fileSplitterFetch[nPos.length-1].start(); [}Z!hq
jccSjGX@w
bNh~=[E
//等待子线程结束 hi0-Sw
//int count = 0; ~{00moN"m
//是否结束while循环 d`sIgll&n
boolean breakWhile = false; kE[Hq-J=N
oR@1/lV
u"5 hlccH
while(!bStop) aB^`3J
{ Aa!#=V1d
write_nPos(); .T*89cEu
Utility.sleep(500); <(tnClAn
breakWhile = true; @g%^H)T
1zGhX]z
c4 bo
for(int i=0;i<nStartPos.length;i++) @3_."-d
{ #-7m@EU;O
if(!fileSplitterFetch.bDownOver) 9Ac4'L
{ pT<}n 9yB5
breakWhile = false; ,7os3~Mk9
break; '<%;Nv
} 7cly{U"
} <BhNmEo)2
if(breakWhile) E2yL9]K2
break; SEsLJ?Dv0
_>(qQ-Px
|5#iPw_wMY
//count++; C252E
//if(count>4) Ct0YwIR*
// siteStop(); cB|Rj}40v
} :WAFBK/x
`xie/
} .'\IR
System.err.println("文件下载结束！"); ?/FCq6o
} .Uh|V-
catch(Exception e){e.printStackTrace ();} /rZ`e'}
} Z{rD4S@^
,Ep41v;T%`
LRKl3"M
//获得文件长度 CINC1Ll_24
public long getFileSize() y4`uU1=
{ )~=g}&
int nFileLength = -1; u>h|A(<
try{ 7f#r&~=
URL url = new URL(siteInfoBean.getSSiteURL()); GcCMCR3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wv-nRDNG
httpConnection.setRequestProperty("User-Agent","NetFox"); #*x8)6Ct
jZP~!q
DY?;Z98P?
int responseCode=httpConnection.getResponseCode(); Q4QF_um
if(responseCode>=400) YLFM3IaP
{ FiW>kTM8
processErrorCode(responseCode); ))eQZ3ap9
return -2; //-2 represent access is error P"ATqQG%D
} l_0/g^(
oz#;7 ?9
,B||8W9
String sHeader; Fv2U@n6'v
OVhtU+r
Olltu"u
for(int i=1;;i++) :Mzkm^7B
{ LL7un_EC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *;X,yEK[
//Utility.log(in.readLine()); 8|H^u6+yz
sHeader=httpConnection.getHeaderFieldKey(i); XpoEZ|0
if(sHeader!=null) ;.#l[
{ X@up=%(
if(sHeader.equals("Content-Length")) U!Eo*?LU$
{ .|x"'3#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xe9V'wICp(
break; x'hUw*
} PBY^m+
} Yb=Z`)
else Lzy Ix!S
break; r E<Ou"
} Ub| -Q
} >gGdzL
catch(IOException e){e.printStackTrace ();} L6IF0`M<,I
catch(Exception e){e.printStackTrace ();} T<S_C$O
X+;{&Efrl
GZk{tTv
Utility.log(nFileLength); O\ph!?L
SVj4K\F
@o4n!Ip2x/
return nFileLength; VKb'!Ystl
} 8V(-S,
\*.u(8~2o
$zYo~5M?i-
//保存下载信息（文件指针位置） $ITh)#Nj
private void write_nPos() yjB.-o('
{ DqbU$jt`
try{ +y\mlfJ.-b
output = new DataOutputStream(new FileOutputStream(tmpFile)); !K5D:x
output.writeInt(nStartPos.length); i\94e{uty[
for(int i=0;i<nStartPos.length;i++) &I=F4 z
{ mCQn '{)
// output.writeLong(nPos); <[w>Mbqj_
output.writeLong(fileSplitterFetch.nStartPos); n1 kh8,
output.writeLong(fileSplitterFetch.nEndPos); 9&7$oI$!J
} hB 36o9|9
output.close(); J sc`^a%`'
} -]e@FNL
catch(IOException e){e.printStackTrace ();} '>0rp\jC
catch(Exception e){e.printStackTrace ();} >+E
} c</u]TD
'X{J~fEI!
"j] r
//读取保存的下载信息（文件指针位置） O0cKmh6=
private void read_nPos() {c\KiWN
{ 6}S1um4 F
try{ o u*`~K|R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jg+q{ ^
int nCount = input.readInt(); 0 $_0T
nStartPos = new long[nCount]; cBz_L"5vr[
nEndPos = new long[nCount]; @A;Ouu(
for(int i=0;i<nStartPos.length;i++) Bgy?k K2[
{ t,>j{SK~
nStartPos = input.readLong(); 'awZ-$#
nEndPos = input.readLong(); .GH#`j
} R<FW?z*
input.close(); +Oa+G.;)o4
} NP< {WL#
catch(IOException e){e.printStackTrace ();} l7M![Ur
catch(Exception e){e.printStackTrace ();} [Adkj
} QH.zsqf(
T3#KuiwU9
"{Jq6):mp
private void processErrorCode(int nErrorCode) ZXL
{ pR*)\@ma
System.err.println("Error Code : " + nErrorCode); Tyk\l>S
} ]<B@g($
* M,'F^E2
2,.;Mdl
//停止文件下载 e~iPN.'1
public void siteStop() #V:28[
{ QXg9ah~
bStop = true; s!Y`1h{
for(int i=0;i<nStartPos.length;i++) )/_T`cN
fileSplitterFetch.splitterStop(); XEvDtDR
U9:w^t[Pp
vh">Z4
} :L'U>)k
} Y,;$RV@g
//负责部分文件的抓取 q]r?s%x
**FileSplitterFetch.java byB ESyV!O
*/ ZuIw4u(9
package NetFox; R;2q=%
/ig'p53jL
iD-,C`
import java.io.*; z=/xv},
import java.net.*; Z;4pI@u
->29Tns
sn6:\X<[
public class FileSplitterFetch extends Thread { A(dWAe,
~D$?.,=l
,OilGTQ#
String sURL; //File URL ~!A*@aC
long nStartPos; //File Snippet Start Position E`aAPk_y
long nEndPos; //File Snippet End Position e"]*^Q
int nThreadID; //Thread's ID Fo86WP}
boolean bDownOver = false; //Downing is over nL]-]n;
boolean bStop = false; //Stop identical <~}#Q,9
FileAccessI fileAccessI = null; //File Access interface 2^.qKY@g@
ZN]LJ4|xu
{:m%n-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e6JT|>9A7
{ rs?"pGz;
this.sURL = sURL; @M!WosRk
this.nStartPos = nStart; IS9}@5`'
this.nEndPos = nEnd; +o7Np|Ou
nThreadID = id; d5z?QI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X'W8 mqk
} eO?.8OM-a
= ^OXP+o
j9XRC9
public void run() f#3U,n8:
{ _xVtB1@kLM
while(nStartPos < nEndPos && !bStop) AO"pm
{ 43p0k&;-7
XKEd~2h<y
)1!jv!
try{ Ous_269cM
URL url = new URL(sURL); UNB'Xjp}@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !0+!%Nr>J
httpConnection.setRequestProperty("User-Agent","NetFox"); {vL4:K
String sProperty = "bytes="+nStartPos+"-"; Ka$YKY,
httpConnection.setRequestProperty("RANGE",sProperty); sMhUVc4
Utility.log(sProperty); b9(_bsc
DL:wiQ
B-`,h pp
InputStream input = httpConnection.getInputStream(); q\fZ Q
//logResponseHead(httpConnection); 0s#`H
P$=BmBq18`
y:>'1"2`
byte[] b = new byte[1024]; @! gJOy
int nRead; >,V~-Tp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K4V\Jj1l
{ | ]DJz
nStartPos += fileAccessI.write(b,0,nRead); ^3B&E^R
//if(nThreadID == 1) <,S5(pZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~VqDh*0
} wx,yx3c (
t"]+}]O
t|ih{0
Utility.log("Thread " + nThreadID + " is over!"); #ARQB2V
bDownOver = true; |*w}bT(PfR
//nPos = fileAccessI.write (b,0,nRead); j~)GZV
} uR:@7n
catch(Exception e){e.printStackTrace ();} @},25"x)
} p[zKc2TPk
} vA r fsgk
=d{B.BP(
9 Z5!3
//打印回应的头信息 !Xzne_V<
public void logResponseHead(HttpURLConnection con) JQtBt2
{ tf5h/:
for(int i=1;;i++) {M.OOEcIp
{ #J,?oe=<4
String header=con.getHeaderFieldKey(i); N5SePA\ ,?
if(header!=null) *C*'J7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yX'f"*
Utility.log(header+" : "+con.getHeaderField(header)); uV@#;c4
else RzOs,
break; S-$N!G~!
} L/U^1=Wi*O
} \:To>A32
v9<'nU WVR
$z>L $,c>
public void splitterStop() 2;z~xR
{ E W{vF|
bStop = true; :=iP_*#
} nSM8o<)H
U>,E]'
Lcx)wof
} xxsax/h
7l%]/`Y-
_Prh&Q1zs
/* srh>" 2."
**FileAccess.java 9uNkd2#
*//文件访问(定位，写) z;dFS
package NetFox; 3Dd"qON!
import java.io.*; ZJ$nHS?ra
Fbpe`pS+V
xejQ!MAB
public class FileAccessI implements Serializable{ ?51Y&gOEZ
!6R;fD#^s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "zn<\z$l
RandomAccessFile oSavedFile; * 7<{Xbsj^
long nPos; 0I`)<o-
/oWn0
eYN=?
public FileAccessI() throws IOException /*zngp@
{ v*.[O/,EBR
this("",0); JjXuy7XQ
} cL]vJ`?Ih
8%@![$q<g
LR:v$3 G(
public FileAccessI(String sName,long nPos) throws IOException a+U^mPe
{ *CIR$sS
oSavedFile = new RandomAccessFile(sName,"rw"); V+A9.KoI
this.nPos = nPos; G<2OL#Y-
oSavedFile.seek(nPos); S[2uez`
} ?>p(*
9ff6Apill
&^v5 x"
public synchronized int write(byte[] b,int nStart,int nLen) pn:) Rq0
{ X{ZcJ8K
int n = -1; Z8X=Md8=
try{ ;V=Y#|o
oSavedFile.write(b,nStart,nLen); eWgqds&#
n = nLen; >o]!-46
} R 2{kS
catch(IOException e) =02$Dwr
{ B=>VP-:
e.printStackTrace (); O3YD jas
} VP7g::Ab
}f~:>N#
+ Z7 L&BI
return n; ,[} XK9
} R;G"LT
7z_EX8^
JJHfg)
} _uYidtxo=
hyHeyDO2
z!M8lpIM
/* 4 Wb^$i!
**SiteInfoBean.java hLv~N}
*/ SH009@l_8
package NetFox; F&Bh\C)]
r+0<A.''a
Z}8khNCYr
public class SiteInfoBean { QGR}`n2D
0Z m^6T
gXNlnh%?S
private String sSiteURL; //Site's URL \W,,@-
private String sFilePath; //Saved File's Path bPlqS+ai_
private String sFileName; //Saved File's Name !nBE[&
private int nSplitter; //Count of Splited Downloading File i-<1M|f
I)JqaM
dHzQAqb8J
public SiteInfoBean() pZ@)9c
{//nSplitter的缺省值为5 |g$n-t
//default value of nSplitter is 5 yDE0qUO
this("","","",5); >-%}'iz+
} @L9C_a
pL& Zcpx
,cesQ ou
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <-]qU}-
{ JNJ96wnX1
sSiteURL= sURL; N<$dbqoT|
sFilePath = sPath; V,*<E&+
sFileName = sName; RZ6[+Ygn
this.nSplitter = nSpiltter; A"V($:>U
/O^aFIxk
'[Ue0r<jn
} c SV`?[a
7K5D,"D;1
9GV1@'<Y]
public String getSSiteURL() e#5LBSP
{ 'o!{YLJ fM
return sSiteURL; _x2i=SFo*$
} Mur)'
I<``d Ne9Q
9tMaOm
public void setSSiteURL(String value) ^%qe&Pe2
{ :pp@x*uNP
sSiteURL = value; ~\{a<-R
} ki8;:m4
fK0VFN8<I
R [[ #r5q
public String getSFilePath() ]RvFn~E!s
{ x(tf0[g
return sFilePath; Hdn%r<+c
} ev{;}2~V
S.I3m-
n&n WY+GEo
public void setSFilePath(String value) j6JK4{
{ .:b&$~<
sFilePath = value; Fhk 8
} >iKbn
jO5,PTV
)Z"
public String getSFileName() , S }
{ 1^HmM"DD
return sFileName; !bq3c(d
} 7~I*u6zY
t/kMV6
w<P$)~6
public void setSFileName(String value) 0p31C7!
{ e!B>M{
sFileName = value; ^E#i5d+'N
} .XVW2ISv
C5F=J8pY
)&") J}@
public int getNSplitter() -Gyj]v5y`c
{ Cd7imj
return nSplitter; YjR`}rdwo
} {tDH !sX
\Qgc7ev
;k=&ZV
public void setNSplitter(int nCount) c{,VU.5/
{ %FhUjHm
nSplitter = nCount; nn?h;KzB
} y!kU0
} %`# HGji)
kR !O-@GJ]
6/=0RTd
/* b)(rlX
**Utility.java d$gT,+|vu
*/ $SbgdbX
package NetFox; nkxv,_)ZT
"8#EA<lsS
JnY.]:
public class Utility { |nMg.t`8
yP^C)
Pe,:FIp,
public Utility() 0|=,!sY
{ `mE>h4
7/969h^s
us7t>EMmB
} IyPk3N
NRI@M5
//线程睡眠 itn<c2UyA
public static void sleep(int nSecond) )L0NX^jW;
{ JP1XH k
try{ [X7KlS9x2
Thread.sleep(nSecond); %ZR<z$
} gy*c$[NS$
catch(Exception e) %jErLg
{ ]=Dzr<*v
e.printStackTrace (); 4/?@%
} ecsQshR
} Re<@.d
|6O7_U#q
//日志 uf/4vz,
public static void log(String sMsg) 2CY4nSKW
{ &~K4I
System.err.println(sMsg); M?ObK#l!_
} ]5',`~jkF
8fSY@
=MjkD)l
public static void log(int sMsg) v1VH&~e
{ W'Y?X]xr
System.err.println(sMsg); }Sr=|j
} AeR*79x
} L&,&SDr
*w`_(Xf
s|[CvjL#0
/* w\zNn4B})A
**TestMethod.java +/n<]?(T
*/ _PPn =kuMa
package NetFox; EGysA{o"X
EpU}~vC9C
)_a;xB`S(
public class TestMethod { WI6h G
X8\UTHT&0
!I jU*c@
public TestMethod() Qv}TUX4
{ ///xx/weblogic60b2_win.exe $e, N5/O
try{ p~3 (nk<+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j_{f(.5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qHl>d*IZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); r]=Z :
fileFetch.start(); =oT4!OUf
} &hcD/*_Z
catch(Exception e){e.printStackTrace ();} ^e{]WH?
zhgvqg-
\OW.?1d
} {WvYb,
8.zYa(<2
>K!$@]2F
public static void main(String[] args) y!VL`xV
{ < #zd]t
new TestMethod(); u10;qYfL8o
} !Bv.@~
} TZ#^AV=ae
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