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)); __LR!F]=i
} 0wQ'~8
for(int i=0;i<nEndPos.length-1;i++) +&bJhX
{ m~c6b{F3Z-
nEndPos = nStartPos[i+1]; VC~1QPC9
} 40h
nEndPos[nEndPos.length-1] = nFileLength; FabgJu
} -]n\|U<
} t}6QU
^__';! e
.6C9N{?Tqf
//启动子线程 %'+}-w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vJI]ZnL{
for(int i=0;i<nStartPos.length;i++) 2zE gAc
{ %JoHc?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EC;R^)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |2AMj0V~
nStartPos,nEndPos,i); 6,Z.RT{5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Mj!\EUn
fileSplitterFetch.start(); <UsFBF
} &lM=>?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )IBvm1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S@4p.NMU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IX+!+XC"U
nEndPos = " + nFileLength); 8/gA]I 6=#
// fileSplitterFetch[nPos.length-1].start(); )@(IhU)
q8 &\;GK|
f^Io:V\
//等待子线程结束 t9l]ie{"o.
//int count = 0; W?TvdeBx
//是否结束while循环 VcX89c4\
boolean breakWhile = false; @3*S:;x
TF_wT28AU2
xB:]{9r
while(!bStop) pf% yEz
{ /qaWUUf
write_nPos(); a=_:`S]}
Utility.sleep(500); CWdpF>En
breakWhile = true; w 3kX!%a:
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7H])2:)
for(int i=0;i<nStartPos.length;i++) u!CcTE*
{ GD-L0kw5
if(!fileSplitterFetch.bDownOver) 9z#z9|hj)3
{ N++ ;}j
breakWhile = false; h~`^H9?M
break; kY?w] lS)t
} W*;r}!ro
} 4++ &P9
if(breakWhile) tNvjwgV\
break; 7?@ -|{
X*w7q7\8-:
[zJ|61^
//count++; tqD=)0Uzs
//if(count>4) ls({{34NF
// siteStop(); ^#gJf*'UE
} 4|/}~9/
8hV>Q
xp*Wf#BF
System.err.println("文件下载结束！"); A1Es>NK[qW
} !&adO,jN+=
catch(Exception e){e.printStackTrace ();} V7<w9MM
} +v+Dkyf:V
y$8S+N?>
2WUl8?f2Y
//获得文件长度 1<G,0Lt
public long getFileSize() )vD:
{ ]P*H,&I`#
int nFileLength = -1; U! $/'Xi9
try{ hG2WxYk
URL url = new URL(siteInfoBean.getSSiteURL()); |mQC-=6t;Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qm/#kPlM
httpConnection.setRequestProperty("User-Agent","NetFox"); (M#m BS
P"{yV?CNg
@$fvhEkrT@
int responseCode=httpConnection.getResponseCode(); RF}R~m9]
if(responseCode>=400) oH(a*i
{ zDf96eK
processErrorCode(responseCode); ;$vVYC
return -2; //-2 represent access is error S&F[\4w5]
} Df@b;-E
m1D,#=C,_
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String sHeader; .I Io
,`!>.E.
\E1CQP-
for(int i=1;;i++) nxJx8d"
{ f5z*AeI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ca["tks
//Utility.log(in.readLine()); 6!@p$ pm)a
sHeader=httpConnection.getHeaderFieldKey(i); >r>pM(h
if(sHeader!=null) c?*x2Vk
{ cwE?+vB
if(sHeader.equals("Content-Length")) [(; .D
{ %O9P|04]3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gI/SA
break; "^)$MAZ
} *7{{z%5Pu
} hAJ^(|
else *SYuq)
break; 4N)45@jk[
} " 1h~P,
} 5Mp$u756
catch(IOException e){e.printStackTrace ();} 0HI0/Tvu$<
catch(Exception e){e.printStackTrace ();} W[LQ$uj
p^C$(}Yh
[dy0aR$>d
Utility.log(nFileLength); G;e)K\[J
19bqz )
by$S#ef
return nFileLength; qFp]jbU
} GPrq(
E~S~Ld%
2;7n0LOs}
//保存下载信息（文件指针位置） =)f.Yf|A*
private void write_nPos() zG7y$\A
{ 8CUl |I ~
try{ MSb0J`
output = new DataOutputStream(new FileOutputStream(tmpFile)); %<>|cO
output.writeInt(nStartPos.length); F6ZL{2$k@
for(int i=0;i<nStartPos.length;i++) 7g4IAsoD
{ ?NxaJ^
// output.writeLong(nPos); K8uqLSP '
output.writeLong(fileSplitterFetch.nStartPos); _6`H`zept
output.writeLong(fileSplitterFetch.nEndPos); +.a->SZ5"
} :n OCs
output.close(); g6h=Q3@
} Yq:+.UU
catch(IOException e){e.printStackTrace ();} l]L"Ex{
catch(Exception e){e.printStackTrace ();} $VeQvm*
} L;U?s2&Y
&S[>*+}{+
z J V>;
//读取保存的下载信息（文件指针位置） Dc3bG@K*G
private void read_nPos() [M?&JA_$}
{ {tuGkRY2~
try{ hdpA& OteR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1`9'.w+r
int nCount = input.readInt(); bLC+73BjC
nStartPos = new long[nCount]; d z\yP v~
nEndPos = new long[nCount]; &g!yRvM!;Q
for(int i=0;i<nStartPos.length;i++) ~"cqFdnO
{ ={I(i6
nStartPos = input.readLong(); 8Ib5
nEndPos = input.readLong(); Sr-!-eC
} h@{CMe
input.close(); [ak[ZXC,
} m,SWG[~
catch(IOException e){e.printStackTrace ();} (wp?tMN5#
catch(Exception e){e.printStackTrace ();} bKQ-PM&I/t
} mW#p&{
`<?((l%;R
FD.L{
private void processErrorCode(int nErrorCode) 4Z/]7Ie
{ lmx'w
System.err.println("Error Code : " + nErrorCode); {WuUzq`
} #Qd"d3QG
?ehUGvV2
(y?`|=G-xT
//停止文件下载 y<)q;fI7
public void siteStop() )C>M74Bt
{ b\+9#)Up@
bStop = true; 41o~5:&
for(int i=0;i<nStartPos.length;i++) KRh?{
fileSplitterFetch.splitterStop(); rlkg.e6
= $6pL
-l$-\(,M`#
} I_'0!@Nn7
} nn/_>%Y
//负责部分文件的抓取 <a=k"'0
**FileSplitterFetch.java Lu~M=Fh
*/ SA.,Q~_T7
package NetFox; G=>LW1E|
lLZ?&z$
k^\>=JTq=
import java.io.*; 6zJ>n~&(
import java.net.*; `f%sq*O~
ea!Znld]
,IG?(CK|
public class FileSplitterFetch extends Thread { 3qq6X?y*
d<v)ovQJ]
ipJnNy;
String sURL; //File URL Z"a]AsG/Q#
long nStartPos; //File Snippet Start Position <9Pf] G=
long nEndPos; //File Snippet End Position D4ud|$s1
int nThreadID; //Thread's ID !\_li+
boolean bDownOver = false; //Downing is over 1 =9 Kwd
boolean bStop = false; //Stop identical z*&r@P -
FileAccessI fileAccessI = null; //File Access interface OEs!H]v
g}'(V>(
O\zGN/!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }t.VH:02y
{ 0V?:5r<
this.sURL = sURL; }P"JP[#E\
this.nStartPos = nStart; df!n.&\y!
this.nEndPos = nEnd; X" ;ly0Mb
nThreadID = id; 44_CT?t<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .p(~/MnO
} =j!Ruy1
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public void run() Fd@:*ER
{ Ov9kD0S
while(nStartPos < nEndPos && !bStop) Zkn1@a
{ >-YWq
w7X], auRC
+#R<emW
try{ NQhlb"Ix
URL url = new URL(sURL); S t0AV.N1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [)83X\CO
httpConnection.setRequestProperty("User-Agent","NetFox"); e025m}%SU
String sProperty = "bytes="+nStartPos+"-"; Gv zw=~8
httpConnection.setRequestProperty("RANGE",sProperty); '}T6e1#JV
Utility.log(sProperty); =H2.1 :'
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&d^u$Y5
InputStream input = httpConnection.getInputStream(); m8njP-CZ
//logResponseHead(httpConnection); W]DZ'
IMay`us]:8
aqAWaO
byte[] b = new byte[1024]; 8k`rj;
int nRead; ok7yFm1\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vd'd@T
{ f.&Y_G3a<
nStartPos += fileAccessI.write(b,0,nRead); OA3* "d*
//if(nThreadID == 1) @AU<'?k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #v`J]I)$
} ~#jD/
B?)=d,E
FGG7;0(
Utility.log("Thread " + nThreadID + " is over!"); v(2|n}qY
bDownOver = true; |,Xrt8O/[
//nPos = fileAccessI.write (b,0,nRead); _o-D},f*e
} _oJq32
catch(Exception e){e.printStackTrace ();} C) "|sG
} *R^ulp[W
} h_Cac@F0
G(XI TL u*
'@<aS?@!t
//打印回应的头信息 pu +"bq
public void logResponseHead(HttpURLConnection con) aPMqJ#fIr
{ s`:-6{E
for(int i=1;;i++) |4s`;4c&
{ +]%d'h
String header=con.getHeaderFieldKey(i); px1{=~V/
if(header!=null) "' hc)58y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |_J[n!~f7
Utility.log(header+" : "+con.getHeaderField(header)); idr,s\$>
else `Vqpo/
break; Q}MS $[y
} 51k^?5cO
} #c ndq[H
A+lP]Oy0S
Qpc+1{BQ
public void splitterStop() &S"ojbb
{ EK6fd#J?1
bStop = true; :}Tw+S5
} R~],5_|
3./4] _p
N3Jfp3_b@
} zp2IpYQ,3
!`G7X
|NcfR"[c
/* gB\KD{E
**FileAccess.java Ex ?)FL$4
*//文件访问(定位，写) `_6!nkq8
package NetFox; jtk2>Ol
import java.io.*; G,8LF/sR
Jyx6{Oj
(f 0p
public class FileAccessI implements Serializable{ TB gD"i-
OwwlQp ~!J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E(e'qL
RandomAccessFile oSavedFile; iG1vy'J#o
long nPos; 1YA_`_@w
O0{M3-
$:%?-xy(
public FileAccessI() throws IOException T/"6iv\1
{ XTHy CK
this("",0); 9LkP*$2"M<
} 1|VnPQqA
wPDA_ns~
wyk4v}
public FileAccessI(String sName,long nPos) throws IOException se9X
{ %:/_O*~)Yg
oSavedFile = new RandomAccessFile(sName,"rw"); .ya^8gM
this.nPos = nPos; hN6j5.x%
oSavedFile.seek(nPos); szC~?]<YY
} N.|Zh+!
s fxQ
#L{QnV.3
public synchronized int write(byte[] b,int nStart,int nLen) OgNt"Vg
{ 4425,AR
int n = -1; dFF[2
try{ &Z_W*D
oSavedFile.write(b,nStart,nLen); W^W^5-'"D,
n = nLen; J3fcnI
} 'Pudy\Ab
catch(IOException e) $-$^r;
{ oXgKuR
e.printStackTrace (); ;/W;M> ^
} (63_
FLO#!G
)k0P' zGb
return n; ~O~c^fLH(B
} WlF"[mU-
M$z.S0"
&j,rq?eh$
} F7`3,SzHp
#;Y JR9VN
:0.Z/s -
/* adh=Kp e!w
**SiteInfoBean.java /a\6&Eb
*/ E0^~i:Mk
package NetFox; *r)/.rK_
E8WOXoP(
LoLmT7
public class SiteInfoBean { 8oG0tX3i
0l6z!@GhT
q28i9$Yqj\
private String sSiteURL; //Site's URL %_wX9ZT
private String sFilePath; //Saved File's Path 2l#Ogn`k
private String sFileName; //Saved File's Name MJJy mi'b
private int nSplitter; //Count of Splited Downloading File SUXRWFl
|A0LYKni
udDhJ?
public SiteInfoBean() nsqs*$
{//nSplitter的缺省值为5 N.C<Mo
//default value of nSplitter is 5 zR/d:P?
this("","","",5); >C~-*M9
} iIq='xwa9
mHo}, |
^ad p<?q4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g]R }w@nJ
{ M-u:8dPu
sSiteURL= sURL; <k'=_mC_
sFilePath = sPath; +qe!KPk2
sFileName = sName; sTO*
this.nSplitter = nSpiltter; E)m{m$Hb
{[PoLOCI
8/*q#j
} *z`_U]tP
h8oG5|Y
$ +;`[b
public String getSSiteURL() @CU3V+
{ _niXl&C
return sSiteURL; -:`$8/A|
} pq7G[
q4<3 O"c1
kJqgY|
public void setSSiteURL(String value) Qwb=N
{ *D1^Se
sSiteURL = value; mc;Z#"kf
} _rXTHo7P
Tm5]M$)
9D:p~_"g
public String getSFilePath() }<o.VY&;.
{ [k.|iCD
return sFilePath; S,Boutd
} \5 IB/*
Yjv}@i"
./LD
public void setSFilePath(String value) >tnQuFKg]
{ quHq?oXV,
sFilePath = value; );V6YE
} TU{^/-l
Y 9]
D)XF@z;
public String getSFileName() o ^L3Xiv
{ XP<wHh
return sFileName; G=!1P]M{
} Zf}]sW$H
6Yebc_, R
eKNZ?!c=
public void setSFileName(String value) *z;4. OX
{ _Iy0-=G
sFileName = value; NARW3\
} y|U3
Tw"u{%t
9nlfb~F~P
public int getNSplitter() * F%Wf
{ EV| 6._Z(D
return nSplitter; cdfJa
} blNJ
)#zc$D^U
rvuskXdo
public void setNSplitter(int nCount) xal+buOiP
{ z=B*s!G
nSplitter = nCount; .ml24SeC
} %N_5p'W
} [ !/u,
4%1sOnl
hIu;\dfwk
/* 0P^RciC f
**Utility.java (:Rj:8{
*/ AJt*48H*G
package NetFox; :@{(^}N8u
JsI`#
m07= _4
public class Utility { yKF"\^`@
Hj't.lg+j
r$}M,! J
public Utility() j'FSd*5m
{ p'fq&a+
M_*"g>Z
ec+&K?T
} A ><
u8L%R[#o
//线程睡眠 P2pdXNV
public static void sleep(int nSecond) i1$ $86
{ G=Hvh=K(
try{ J7q^4M+o:
Thread.sleep(nSecond); @igr~hJ
} /]m5HW(P7K
catch(Exception e) S0\QZ/je
{ U8qb2'a8
e.printStackTrace (); U;u@\E@2
} ~kPHf_B;z
} ]W39HL
:,%~R2
//日志 $(B|$e^:(
public static void log(String sMsg) ^N#B(F
{ \=PnC}7I
System.err.println(sMsg); Wsya:9|
} {Qbg'|HO=l
7{>mm$^|V
9$ZQuHSw7
public static void log(int sMsg) 8&<C.nKP
{ &SuWmtq
System.err.println(sMsg); H<41H;m
} ewHk (ru
} %^tKt
wb~BY
Hc^q_{}"
/* l =~EweuM
**TestMethod.java 5<ZE.'O
*/ &{E1w<uv
package NetFox; koDIxj'%X
x6Zhw9RV
v&Xsyb0CaM
public class TestMethod { Pj(DlC7G,
ChzKwYDY
C$?gt-tJ'
public TestMethod() L!G]i;=:
{ ///xx/weblogic60b2_win.exe MJ"ug8N
try{ 3NU{7,F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J=?`~?Vbo
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7u7`z%
SiteFileFetch fileFetch = new SiteFileFetch(bean); B8A-|S!,U
fileFetch.start(); T40&a(hXQ
} EQ< qN<uW
catch(Exception e){e.printStackTrace ();} Z./$}tVUG
%;ST7
E;m]RtvH
} VRden>vKN
DmzK* O{
mY6d+
public static void main(String[] args) 0?c2=Y
{ cW%QKdTQY0
new TestMethod(); ! Rrk
} j#4 Iu&YJ
} 5B6twn~[
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