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)); y8hg8J|
} .x!7
for(int i=0;i<nEndPos.length-1;i++) gZ"{{#:}
{ >3`ctbe
nEndPos = nStartPos[i+1]; nqxq@.L2
} VuMDV6^Z
nEndPos[nEndPos.length-1] = nFileLength; sRyw\v-=P
} 2v9s@k/k)6
} K%c ATA3
"56?/ jF
+Bq}>
//启动子线程 gLaO#cQ%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =3sldKL&F
for(int i=0;i<nStartPos.length;i++) ,AbKxT f2
{ :@>br+S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dd# SUQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SZ2q}[o`R
nStartPos,nEndPos,i); }C{}oLz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q)6wkY+!
fileSplitterFetch.start(); d0A\#H_&
} \ ~LU 'j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sK 1m9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [B~zoB(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L.0} UXd
nEndPos = " + nFileLength); 32 1={\X
// fileSplitterFetch[nPos.length-1].start(); 2Ph7qEBQ22
P\X=*
~6:LUM
//等待子线程结束 {{]=zt|69
//int count = 0; /y](mu"!
//是否结束while循环 QK?2E
boolean breakWhile = false; ?St=7a(D
YoF\MT]W
!HR2Rfl
while(!bStop) 38U5^`
{ 2u~c/JryN
write_nPos(); Xrj(,|
Utility.sleep(500); |.8d,!5w}
breakWhile = true; kg?T$}O
11B{gUv.]
ll(e,9.D
for(int i=0;i<nStartPos.length;i++) mF*?e/
{ A)RI:?+
if(!fileSplitterFetch.bDownOver) 6t_ 3%{
{ DYAwQ"i;6
breakWhile = false; uq|vNLW26
break; Lov.E3S6;
} %89"A'g
} P )t]bS
if(breakWhile) n~,]KdU]
break; 8sR
EFRZ% Y
B;z>Dd,Y_x
//count++; #0?"J)
//if(count>4) Zr.\`mG4f
// siteStop(); vNC$f(cQ
} h{W$ fZc<
Y|m_qB^_
qD(fYOX{C
System.err.println("文件下载结束！"); rysP)e
} )e|$K= D
catch(Exception e){e.printStackTrace ();} k+WO &g*|
} FtFv<UV
C`NBHRa>
s`Yu"s 8}4
//获得文件长度 iJ`%yg,
public long getFileSize() N?a1sdR
{ N"YK@)*Q
int nFileLength = -1; :jk)(=^
try{ ~{7zm"jN
URL url = new URL(siteInfoBean.getSSiteURL()); {WYu0J@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hF{x')(#l
httpConnection.setRequestProperty("User-Agent","NetFox"); jU]]:S4xD/
`P^u:
{k_ PMl0G
int responseCode=httpConnection.getResponseCode(); o%V @D'w
if(responseCode>=400) d,Cz-.'sOf
{ 0a2$P+p
processErrorCode(responseCode); &TP:yA[
return -2; //-2 represent access is error F@=e2e 4
} }[>RxHd
io9y;S"+
VM-qVd-
String sHeader; _=|nOj39
s6uF5]M;2
)|U_Z"0H^
for(int i=1;;i++) ,zAK3d&hj
{ bU;}!iVc]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Mvy6"Q:
//Utility.log(in.readLine()); +=ZWau
sHeader=httpConnection.getHeaderFieldKey(i); :"M9*XeHO
if(sHeader!=null) -Q<z1vz
{ FF%\gJ
if(sHeader.equals("Content-Length")) OwG6i|q
{ jzl?e[qPA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aUypt(dv
break; .mvB99P{<
} :`+|'*b(A
} Smqr q
else IvEMg2f}
break; hH<6E
} 94~"U5oQ:
} p!HPp Ef+#
catch(IOException e){e.printStackTrace ();} "XGD:>Q.
catch(Exception e){e.printStackTrace ();} W<\kf4Y
r+t ,J|V
|rr$U
Utility.log(nFileLength); "bD+/\ z
@T<ad7g-2J
c@RT$Q9j
return nFileLength; opm?':Qst
} p+orBw3
9U#\nXM
Z{Vxr*9oO
//保存下载信息（文件指针位置） +dqk6RE
private void write_nPos() OZ(Dpx(Q
{ a$C2}
try{ Ho|o,XvLv
output = new DataOutputStream(new FileOutputStream(tmpFile)); hMNJ'i}
output.writeInt(nStartPos.length); <\ y!3;
for(int i=0;i<nStartPos.length;i++) k0H?9Z4k5
{ NFB*1_m
// output.writeLong(nPos); 6N9 c<JC
output.writeLong(fileSplitterFetch.nStartPos); n11LxGwk
output.writeLong(fileSplitterFetch.nEndPos); E)C.eW /
} ~'NX~<m
output.close(); yOX&cZ[
} %9t{Z1$
catch(IOException e){e.printStackTrace ();} nAIH`L"X
catch(Exception e){e.printStackTrace ();} 5JS ZLC
} xLA~1ZSVJw
}sf YCz
)HEfU31IC
//读取保存的下载信息（文件指针位置） WHp97S'd
private void read_nPos() TNh=4xQ}
{ J"diFz+20
try{ fx<FIj7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sB?2*S"X)<
int nCount = input.readInt(); 8$\Za,)g
nStartPos = new long[nCount]; 6tOCZ'f
nEndPos = new long[nCount]; ?Fce!J
for(int i=0;i<nStartPos.length;i++) RTK}mhnV
{ 9z #P
nStartPos = input.readLong(); J5O.*&
nEndPos = input.readLong(); ID)^vwn
} gh TcB
input.close(); qv *3A?uzr
} 24//21m
catch(IOException e){e.printStackTrace ();} XAkK:}h
catch(Exception e){e.printStackTrace ();} E[S? b=^
} Iha[Gu
;xfO16fNk
haCKv
private void processErrorCode(int nErrorCode) 92ZWU2"
{ ovo/!YJ2
System.err.println("Error Code : " + nErrorCode); CK2B
} y>$1UwQ
B1E$v(P3M
'0Lov]L
//停止文件下载 nt=x]wEC
public void siteStop() P^"R4T
{ M~als3
bStop = true; H#+\nT2m
for(int i=0;i<nStartPos.length;i++) jk )Vb
fileSplitterFetch.splitterStop(); 3S5^`Ag#
@|BD|{k
uG;?vvg>
} PkTfJQP8
} [cDbaq,T
//负责部分文件的抓取 cA<<&C
**FileSplitterFetch.java H#35@HF*o
*/ 3 -tO;GKb
package NetFox; Dv@PAnk3C
{-HDkG' 8
s2^B(wP
import java.io.*; sm1;MF]/u
import java.net.*; k=?^){[We
Jn=42Q:>
\]I
public class FileSplitterFetch extends Thread { 8"x9#kyU<3
(_K_`5d;QI
)Ob]T{GY
String sURL; //File URL X'f)7RbT
long nStartPos; //File Snippet Start Position FqwIJ|ct
long nEndPos; //File Snippet End Position \ZMP_UU(
int nThreadID; //Thread's ID C,"=}z1P
boolean bDownOver = false; //Downing is over bG(x:Py&
boolean bStop = false; //Stop identical |H W( vA
FileAccessI fileAccessI = null; //File Access interface +oZH?N4yaM
b0 &
+Qs!Nhsq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C`NmZwL
{ =p q:m
this.sURL = sURL; DVh)w}v
this.nStartPos = nStart; MWs~#ReZ
this.nEndPos = nEnd; hk_g2g
nThreadID = id; @.gPJMA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F}'wH-qp
} X'x3esw w
V.8%|-d
[/cIUQ
public void run() hU"F;4p
{ ($62o&I
while(nStartPos < nEndPos && !bStop) RDJ+QOVKg
{ F+ukAT
\lEkfcc
2bLI%gg3
try{ PO o%^'(
URL url = new URL(sURL); ?v4E<iXs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .x-J44i@/
httpConnection.setRequestProperty("User-Agent","NetFox"); 3+(z_!Qh
String sProperty = "bytes="+nStartPos+"-"; 1k[GuG%/K
httpConnection.setRequestProperty("RANGE",sProperty); % :/_f
Utility.log(sProperty); j;\[pg MR/
l^W uS|G[
CxDcY
InputStream input = httpConnection.getInputStream(); s8vKKvs`9
//logResponseHead(httpConnection); OCNPi4
Yw)Fbt^
?3q@f\fZ
byte[] b = new byte[1024]; n@ [
int nRead; o=_c2m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zkexei4^<
{ yMxTfR
nStartPos += fileAccessI.write(b,0,nRead); g^l RG3a
//if(nThreadID == 1) OJ1tV% E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YQd:M%$
} ? ?[g}>
#jA)>z\Q^
{@.Vh]
Utility.log("Thread " + nThreadID + " is over!"); ,T|x)"uA`
bDownOver = true; VagT_D
//nPos = fileAccessI.write (b,0,nRead); 66\jV6eH7L
} +Gh7^v|"
catch(Exception e){e.printStackTrace ();} Y#HI;Y^RP
} 6B6vP%H#
} }x:f%Z5h
gXy-Mpzp
gU;&$
//打印回应的头信息 Ck'aHe22'
public void logResponseHead(HttpURLConnection con) cb$-6ZE/
{ vFQ,5n;fF
for(int i=1;;i++) O0huqF$K
{ iw\%h9
String header=con.getHeaderFieldKey(i); LFf`K)q
if(header!=null) QyGnDomQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;Vu5p#,O<M
Utility.log(header+" : "+con.getHeaderField(header)); RMP9y$~3pU
else (9C<K<
break; Kat&U19YH
} 7L3ik;>
} F)Oe9x\/
[6tSYUZs
%j+xgX/&
public void splitterStop() )T|L,Lp
{ %J~WC$=Qv
bStop = true; p&Ed\aQ%z;
} _O]xey^r
:50b8
p2%
} )uheV,ZnY
}}r> K}
FN^FvQ
/* GP a`e
**FileAccess.java PaWr[ye
*//文件访问(定位，写) $`J_:H%
package NetFox; #07!-)Gv
import java.io.*; t ^SzqB
eu#'SXSC F
se9>.}zZN
public class FileAccessI implements Serializable{ _$s> c!t,#
IV`%V+ f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'LSz f/w
RandomAccessFile oSavedFile; ytAWOt}`
long nPos; \6!W05[ Q
A1i!F?X
(u1m]WYL
public FileAccessI() throws IOException oBQm05x"
{ h2Bz F
this("",0); 3V<&|
} >I"V],d!6
)>a B
5&!c7$K0
public FileAccessI(String sName,long nPos) throws IOException {XCf-{a]~
{ 9KuD(EJS
oSavedFile = new RandomAccessFile(sName,"rw"); G}nO@
this.nPos = nPos; cr;`Tl~}s
oSavedFile.seek(nPos); +^|iZbZKx
} aSutM
r'7LR
S<wj*"|.s
public synchronized int write(byte[] b,int nStart,int nLen) PoSpkJH
{ a;AzY'R
int n = -1; Dt|)=a
try{ EHf\L
oSavedFile.write(b,nStart,nLen); `'S0*kMT
n = nLen; 9 ;i\g=
} Cb;WZ3HR
catch(IOException e) %;xOB^H^
{ ~@W*r5/
e.printStackTrace (); Kg\R+i@#<
} K }$&:nao
3L5r*fa
U9hS<}<Ki
return n; OQ&'Dti
} RP4Ku9hk
` uCIXb
{FO$yw=>
} dt\jGD
G4 _,
%3r:s`{
/* KKe8 ly,
**SiteInfoBean.java "tk-w{>
*/ "Zv~QwC
package NetFox; $A_]:qI2
%kshQ%P)?
Q>< 0[EPj3
public class SiteInfoBean { <.K4JlbT
9LJZ-/Wq
YX*x&5]lq
private String sSiteURL; //Site's URL 8+Llx
private String sFilePath; //Saved File's Path c3%@Wj:fo
private String sFileName; //Saved File's Name `{v?6:G:Q
private int nSplitter; //Count of Splited Downloading File BqK(DH^9N
!~i' -4]
Z~
public SiteInfoBean() 3>M&D20Z
{//nSplitter的缺省值为5 !U%T&?E l
//default value of nSplitter is 5 >w6taX
this("","","",5); fh8j2S9J
} s"KJiQKGM
),:c+~@@kT
~Heb1tl;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R\3VB NX.g
{ K$ }a8rH
sSiteURL= sURL; 5Qwh(C^H
sFilePath = sPath; AM"jX"F9/
sFileName = sName; ENVk{QE!
this.nSplitter = nSpiltter; #18FA|
d~J-|yyT
OWp%v_y]
} B5%n(,Lx
`mfq 2bVc
/UcV
public String getSSiteURL() uP $Cj
{ zw<p74DH
return sSiteURL; . 5y"38e
} ZzGahtx)Y
ym,H@~
)::>q5c
public void setSSiteURL(String value) 9# 4Y1LS)
{ #FOqP!p.E
sSiteURL = value; Cs3^9m6;d
} )m3Uar
/wShUR{
W<ZK,kv
public String getSFilePath() O)|P,?
{ AFvgbn8Qh
return sFilePath; O43YY2
} INs!Ame2
] Wy)
Psura$:
public void setSFilePath(String value) [&[^G25
{ hY5WJ;
sFilePath = value; f"u*D,/sS
} <:>SGSE9
&GTI
}TQ{`a@
public String getSFileName() Am0{8 '
{ Qhi '')Q
return sFileName; Y/<lWbj*A
} '+>fFM,*B
/ O/`<
7M_U2cd|TD
public void setSFileName(String value) gbeghLP[?
{ /I5X"x
sFileName = value; :AdDLpk3j
} n6d9\
V"o7jsFH6n
Jf)bHjC_V
public int getNSplitter() u=F+(NE"
{ \6?A!w~6
return nSplitter; #o/H~Iv
} 5Z/GK2[HL
/M~!sPW&?
cq&*.
public void setNSplitter(int nCount) 'TC/vnM
{ .MW@;
nSplitter = nCount; &;,,H< p
} enNiI$H]`_
} 93qwH%
`!:q;i]}
1% F?B-k
/* r"2V
**Utility.java 7'-Lp@an
*/ 9j]sD/L5q
package NetFox; HmfG$Z
X:a`B(@S
a {}|Bf<
public class Utility { <}U'V}g
L9Z;:``p
RgorkZlVM
public Utility() ,mS/h~-5n
{ SVlua@]ChU
Ok7t@l$
w~_;yQ
} o@]So(9f
o*x*jn:hm
//线程睡眠 p(xC*KWB
public static void sleep(int nSecond) XoLJL]+?
{ 6$a$K,dZ
try{ $WYbm}j
Thread.sleep(nSecond); I$NhXZ)KT
} EV#MQM
catch(Exception e) tkQH\5
{ =~Ynz7 /x
e.printStackTrace (); )#a[-.OI
} JXG"M#{
} &zQ2M#{82
Cz4)Yz
//日志 `b8v1Os^2
public static void log(String sMsg) +')f6P;t>=
{ =cN&A_L(
System.err.println(sMsg); Y={&5Mir
} RjF'x
G$'jEa<:u
v5;I]?72l~
public static void log(int sMsg) 9Suu-A
{ d_n7k g+
System.err.println(sMsg); ;N B:e
} <2!v(EkI
} >{eCh$L
g~7Ri-"
FJ*i\Q/D
/* ]sz3]"2
**TestMethod.java Q%/<ZC.Mz6
*/ ,\ 2a=Fp
package NetFox; 4!asT;`'
Q6o(']0
R1F5-#?'E
public class TestMethod { {7!UQrm<
)eUW5 tS
T5Q{{@Q
public TestMethod() 'Y$R~e^Y?
{ ///xx/weblogic60b2_win.exe `c/*H29
try{ Y+4o B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8ul&x~2;X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8<mjh0F-,
SiteFileFetch fileFetch = new SiteFileFetch(bean); sS&Z ,A
fileFetch.start(); \;VhYvEH
} ve ~05mg
catch(Exception e){e.printStackTrace ();} M3p
"'g[1Li
-",=G\XZ
} *Nyev]8
`X,yM-(
rC:?l(8ng3
public static void main(String[] args) L,d LE-L
{ TI9UXa:V\
new TestMethod(); w ;daC(:
} hYQ_45Z*?
} *A}cL
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