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)); mj^]e/s%
} n<3*7/-
for(int i=0;i<nEndPos.length-1;i++) h_?#.z0ih;
{ 1z5\>F
nEndPos = nStartPos[i+1]; Yv7`5b{N.
} +`$[h2Z=:
nEndPos[nEndPos.length-1] = nFileLength; otSF8[
} -_xC,dwK
} ;d{lvKk
h 1`yW#%
t1%<l
//启动子线程 Q"QL#<N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .!`v2_
for(int i=0;i<nStartPos.length;i++) eF%IX
{ j[q$;uSD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @ZFU< e$!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NX5NE2@^qH
nStartPos,nEndPos,i); uom~,k$|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /ar/4\b
fileSplitterFetch.start(); _!'sj=n]q
} _0c$SK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,Z1W3;O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0Q= o"@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {I~[a#^
nEndPos = " + nFileLength); QnPgp(d<
// fileSplitterFetch[nPos.length-1].start(); MI<XLn!*
z6 A`/ jF}
nbM7 >tnsk
//等待子线程结束 .}||!
//int count = 0; RI2Or9.
//是否结束while循环 x|oa"l^JZ"
boolean breakWhile = false; 2`]_c=
Qx%]u8s
W;9Jah.
while(!bStop) %G>|u/:U
{ k3FpD=N
write_nPos(); x[i Et%_
Utility.sleep(500); G*$a81dAX
breakWhile = true; VtJy0OGcRP
T.j&UEsd
g0~3;y
for(int i=0;i<nStartPos.length;i++) }^/;8cfLY
{ -a(\(^NW
if(!fileSplitterFetch.bDownOver) Z<t(h=?
{ fqgm`4>
breakWhile = false; xw%'R-
break; 7Yjxx+X9
} 9X2lH~C
} gc6T`O-_;
if(breakWhile) wcI4Y0+J
break; WP-'gC6K=
.Iret:
!agtgS$qII
//count++; /\B[lRn
//if(count>4) gUq)M
// siteStop(); {=Ku9\
} v8L&F9 o
+v}R-gNR
(KDv>@5
System.err.println("文件下载结束！"); w'b|*_Q4Q
} xp>p#c
catch(Exception e){e.printStackTrace ();} 95G*i;E
} 9ywPWT[^
.+"SDtoX
T'TxC)
//获得文件长度 s`$px2Gw
public long getFileSize() vs)1Rm
{ @Fl&@ $
int nFileLength = -1; cKj6tT"=O
try{ Cq0S8Or0
URL url = new URL(siteInfoBean.getSSiteURL()); H@8g 9;+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UkY `&&ic
httpConnection.setRequestProperty("User-Agent","NetFox"); &xwAE*}
=k(~PB^>
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int responseCode=httpConnection.getResponseCode(); XU}sbbwu
if(responseCode>=400) jKcnZu
{ 2Rp'ju~O)/
processErrorCode(responseCode); K)!?np{km
return -2; //-2 represent access is error #^bkM)pc
} [@qUQ,Ie
3GSoHsNk
Ye8&cZ*.
String sHeader; sDH|k@K
')ErXLP_
&dV|~xA6N
for(int i=1;;i++) FB0y
{ 8'2lc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +c699j;[
//Utility.log(in.readLine()); R":nG7o
sHeader=httpConnection.getHeaderFieldKey(i); p5KM(N6f
if(sHeader!=null) f]BG`rJX
{ E&/D%}Wl
if(sHeader.equals("Content-Length")) "5-S:+
{ hOX$|0i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1MV\ ^l_
break; _`JYA
} <h/\)bPB
} oK GFDl]3
else p,=:Ff}~
break; "}bk *2
} $o"PQ!z
} C_[V[k0(
catch(IOException e){e.printStackTrace ();} <N%8"o
catch(Exception e){e.printStackTrace ();} \Mv8pU
;n*N9-|.
O/IW.t
Utility.log(nFileLength); qO<'_7TN[
xy%lp{
ua['rOnU
return nFileLength; dQ8}mH!
} UC^Bn1
W"rX$D[Le
1GY[1M1^
//保存下载信息（文件指针位置） N[j7^q7Xt
private void write_nPos() #=f ]"uM<
{ W?"Z>tgp
try{ yD`{9'L -
output = new DataOutputStream(new FileOutputStream(tmpFile)); >?,arER
output.writeInt(nStartPos.length); ?wps_XU
for(int i=0;i<nStartPos.length;i++) lHpo/R:
{ U4_<
// output.writeLong(nPos); *HmL8c
output.writeLong(fileSplitterFetch.nStartPos); C.{*|#&GAt
output.writeLong(fileSplitterFetch.nEndPos); icF -`m
} _c|>m4+X
output.close(); 7cn"@h rJ
} ,>%AEN6N2
catch(IOException e){e.printStackTrace ();} 3:a}<^DuCS
catch(Exception e){e.printStackTrace ();} ]D7z&h
} B{W2D
oOuhbFu
1;ulqO
//读取保存的下载信息（文件指针位置） i4.s_@2Y
private void read_nPos() S\Qh#yFT
{ #](k,% 2
try{ 4];Qpln
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x#e(&OjN7
int nCount = input.readInt(); Y9m'RFZr
nStartPos = new long[nCount]; {=7W;uL
nEndPos = new long[nCount]; HLAYmXX"w
for(int i=0;i<nStartPos.length;i++) V9"Kro
{ joifIp_
nStartPos = input.readLong(); =MG
nEndPos = input.readLong(); )\uy 0+b
} 5cP]
input.close(); p;) ;Vm+8
} -o F#a 8
catch(IOException e){e.printStackTrace ();} pF.Ws,nQ5
catch(Exception e){e.printStackTrace ();} :Qu!0tY
} <W vuW6
MUNeGqv
qTiUha9
private void processErrorCode(int nErrorCode) C%v@u$N
{ -,96Qg4vI
System.err.println("Error Code : " + nErrorCode); 0At??Zpy
} b]mRn{r?
0i$jtCCL(
kT UQ8U
//停止文件下载 9U58#
public void siteStop() /U)w:B+p/g
{ +U^dllL7
bStop = true; ap\2={u^|
for(int i=0;i<nStartPos.length;i++) g4d5G=y
fileSplitterFetch.splitterStop(); mCtuyGY
w"-bO ~5h
V/|Ln*rm
} t9m:E
} E[LXZh
//负责部分文件的抓取 gi:;{
**FileSplitterFetch.java Ih`n:aA
*/ uGJeQ
package NetFox; \XMl8G
Lq LciD
)TM![^d
import java.io.*; N{P (ym2yR
import java.net.*; 1_/\{quE
D}!U?]la&
R]/F{Xs
public class FileSplitterFetch extends Thread { ^k^%w/fo
b_Ba0h=
I]Wb\&$
String sURL; //File URL |MMr}]`
long nStartPos; //File Snippet Start Position iml*+t
long nEndPos; //File Snippet End Position %dL|i2+*8
int nThreadID; //Thread's ID "=|yM~V
boolean bDownOver = false; //Downing is over Ff& VBm
boolean bStop = false; //Stop identical LjXtOF
FileAccessI fileAccessI = null; //File Access interface *kL1r w6
5.VA1
7=T0Sa*;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f]5bAs
{ ET_}x7
this.sURL = sURL; >g93Bj*
this.nStartPos = nStart; )J (ekfM
this.nEndPos = nEnd; Aid{PGDk
nThreadID = id; $F G4wA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &.<{c `-
} :!tQqy2
5qG7LO.
X/i8$yqv
public void run() :n'QNGj
{ ,)GCg@7B
while(nStartPos < nEndPos && !bStop) gNLjk4H,S[
{ X^9_'T9
pPh_p@3I
{(7.X4\x
try{ q97Dn[>3
URL url = new URL(sURL); +#Ov9b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )_.@M '?
httpConnection.setRequestProperty("User-Agent","NetFox"); h{<^?=
String sProperty = "bytes="+nStartPos+"-"; |EU}&k2
httpConnection.setRequestProperty("RANGE",sProperty); 0<v~J9i
Utility.log(sProperty); )zUV6U7v
fb`VYD9[^
qI;k2sQR
InputStream input = httpConnection.getInputStream(); "VcGr#zW
//logResponseHead(httpConnection); hUA3(!0)
C _[jQTr
,*S?L qv^
byte[] b = new byte[1024]; 3tIIBOwg[
int nRead; 1oX"}YY1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~Zaxn~u:
{ sur2Mw(M"
nStartPos += fileAccessI.write(b,0,nRead); rM bb%d:
//if(nThreadID == 1) ,=6Eju#P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r*+9<8-ZX<
} VWfrcSZg6M
mW8CqW\Q5
Jz%&-e3
Utility.log("Thread " + nThreadID + " is over!"); :?RK>}4|F
bDownOver = true; S~Q7>oNm
//nPos = fileAccessI.write (b,0,nRead); Z/beROW)
} wM!QU{Lz
catch(Exception e){e.printStackTrace ();} A|Y\Y}
} y62;&{?m
} ItOVx!"@9
5QSd$J
`i{o8l
//打印回应的头信息 >r]# 77d
public void logResponseHead(HttpURLConnection con) Mh_jlgE'd#
{ g4Hq<W"
for(int i=1;;i++) z=ppNP0
{ Nb]qY>K
String header=con.getHeaderFieldKey(i); )b!q
if(header!=null) <o?qpW$,>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YT:<AJm
Utility.log(header+" : "+con.getHeaderField(header)); qU2>V
else C7+TnJ
break; k9R1E/;
} 1Tiq2+hmf
} HHEFX9u
Iv/yIS
`+zr PpX
public void splitterStop() uft~+w P
{ Xd|5{
bStop = true; 3tLh{S?uJ
} mDV 2vg
^Gd<miw
9w0 ^=
} n:<avl@o<
y/i"o-}}~|
2_F`ILCML
/* ,cC4d`
**FileAccess.java F=P|vYL&&
*//文件访问(定位，写) OH)SdSBz
package NetFox; *"e[au^8*b
import java.io.*; Zs{ `Yf^Q
)Fm
-OkKLub
public class FileAccessI implements Serializable{ B:x4H}`vh
zcZr )Oh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n.A[Z
RandomAccessFile oSavedFile; /VJ@`]jhDf
long nPos; 9L&AbmIr
s{iYf :
a[#4Oq/t$
public FileAccessI() throws IOException f%@Y XGf
{ t"BpaA^gO
this("",0); ekAGzu
} RNt3az
,bH
| c8u
public FileAccessI(String sName,long nPos) throws IOException CyXcA;H,.
{ ^WD[>E~
oSavedFile = new RandomAccessFile(sName,"rw"); mU\$piei
this.nPos = nPos; r%B5@+{so
oSavedFile.seek(nPos); xMuy[)b
} ]}5jX^j
b?y1cxTT
c|O5Vp}
public synchronized int write(byte[] b,int nStart,int nLen) 3}T&|@*
{ >2C;5ba
int n = -1; <N`rcKE%~P
try{ j5/H#_.
oSavedFile.write(b,nStart,nLen); 75v*&-
n = nLen; RyM2CQg[
} 6Q wL
catch(IOException e) `zsKc 6%
{ ]mqB&{g
e.printStackTrace (); u>? VD%
} (ZI&'"H
I'yhxymZ;
74[}AA
return n; 1zp,Suv
} }h]:I'R!
68_UQ.
)0'O!O
} <A6<q&g|E
"3>#[o
5VPuHY2
/* f'.yM*
**SiteInfoBean.java j<gnh
*/ }3i@5ctQ
package NetFox; :#|77b0
*yX_dgC>[
?=T&|pp
public class SiteInfoBean { j1d=$'a "
,~kMkBkl~
-51L!x}1c
private String sSiteURL; //Site's URL }=L >u>cP
private String sFilePath; //Saved File's Path uC}YKT>V7
private String sFileName; //Saved File's Name Cy2X>Tl"<E
private int nSplitter; //Count of Splited Downloading File \o3i9Q9C
(<<eHf,@
+22[ h@
public SiteInfoBean() ahf$#UQLb
{//nSplitter的缺省值为5 @a3<fmJ
//default value of nSplitter is 5 *Js<VR
this("","","",5); 5_i&}c23Vn
} 9c?izpA
lA ,%'+-
4t+88e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U$J]^-AS
{ |zUDu\MZ{
sSiteURL= sURL; xFvSQ`sp
sFilePath = sPath; XH*^#c
sFileName = sName; 0GG;o[<
this.nSplitter = nSpiltter; x Dr^&rC
&\(YmY
[+%*s3`c#
} uL= \t=
jjbw.n+1
u9&p/qMx2
public String getSSiteURL() i4-L!<bJ
{ {:dE_tqo
return sSiteURL; p75w^
} b"Ulc}$/&
Q{a!D0;4v
3 (<!pA
public void setSSiteURL(String value) lWdE^-
{ tDwXb>
sSiteURL = value; '-~86Q
} KA<
H_2hr[
*X>rvAd3
public String getSFilePath() *%8us~w5/
{ 9Z*vp^3
return sFilePath; !XicX9n
} !hc7i=V?
- Z|1@s&
`2Z=Lp
public void setSFilePath(String value) /bb4nM_E/
{ {.2C>p
sFilePath = value; yQW\0&a$
} `=>Bop)
1,mf]7k$
o60wB-y
public String getSFileName() [|>.iH X
{ msCAC*;,
return sFileName; xtnB:3
} '(Bs<)(H
xM*v!J,
HC0puLt_
public void setSFileName(String value) k~gQn:.Cx
{ jgYiuM3c\
sFileName = value; $@NZ*m%?JQ
} N7;2BUIXJ
M-Js"cB[
C$hsR&
public int getNSplitter() <FJ#Hy+
{ gsR"d@!
return nSplitter; vS0P]AUo
} byMO&Lb*
r9%W?fEBp
#eaey+~
public void setNSplitter(int nCount) f(C0&"4e
{ h>n;A>k@N
nSplitter = nCount; }Yt0VtLt
} " c]Mz&z
} 3HA{18{4uP
2D!'7ZD
5M(?_qj
/* FxUH?%w
**Utility.java 3Q#VD)
*/ B845BSmh
package NetFox; BBx"{~
IFE C_F>
OO$<Wgh
public class Utility { s810714
*= D$
IKU-
public Utility() dV5$L e#y
{ /yOd]N;$
pUPb+:^R
J3zb_!PPE
} =y4g. J\
kSJWQ
//线程睡眠 fT@#S}t
public static void sleep(int nSecond) !9!Ns(vUM
{ ecFI"g
try{ o0/03O
Thread.sleep(nSecond); Qh*|mW
} OUs2)H61
catch(Exception e) !At_^hSqz
{ X=JSqO6V9
e.printStackTrace (); OVd"'|&6_
} *=I#VN*_<.
} ~/NA?E-c
zso.?`85
//日志 ^qDkSoqC"
public static void log(String sMsg) 55;xAsG
{ _zOzHc?Q
System.err.println(sMsg); dv,8iOL
} IlE! zRA
p7k0pSt
Q`oi=OYB
public static void log(int sMsg) #e#8I7P
{ A>PM'$"sT
System.err.println(sMsg); *L^{p.K4
} =tP|sYR]^
} )sL:iGU
mg;qG@?
W w8[d
/* N( /PJJ~
**TestMethod.java !Khsx
*/ Pc$<Cv|vz
package NetFox; =HSE
c_".+Fa
$$8"i+,K
public class TestMethod { 9LFg":
T&!>lqU!J
+zlaYHj
public TestMethod() GJW1|Fk
{ ///xx/weblogic60b2_win.exe E:i3 /Ep?
try{ KctD=6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r^@*Cir
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qH-dT,`"{
SiteFileFetch fileFetch = new SiteFileFetch(bean); O,bj_CWx
fileFetch.start(); fg,~[%1
} k_^d7yH
catch(Exception e){e.printStackTrace ();} MTF:mLJ
2x{3'^+l
>g F
} $EtZ5?qS
fkx 9I m4
2L,e\]2Z
public static void main(String[] args) PGybX:L
{ YsTfv1~z#
new TestMethod(); zX5p'8-
} d8x$NW-s
} ?W#! S
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