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)); c'$y_]
} 8?~>FLWTXZ
for(int i=0;i<nEndPos.length-1;i++) a[t"J*0
{ V xN!Ki=
nEndPos = nStartPos[i+1]; i@{b+5$
} #~Kno@
nEndPos[nEndPos.length-1] = nFileLength; j\#)'>"
} Jn(|.eT|
} O-AC$C[d
El}~3|a?
]_ LAy
//启动子线程 kb-XEJ}L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;180ct4
for(int i=0;i<nStartPos.length;i++) 1xxTI{'g[
{ BDN}`F[F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JA >&$h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *h?*RUQ
nStartPos,nEndPos,i); BDp(&=ktq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); axG%@5
fileSplitterFetch.start(); NrcV%-+u%
} B <Jxj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RCkmxO;b&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); __z/X"H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }2=~7&)
nEndPos = " + nFileLength); c7rC!v
// fileSplitterFetch[nPos.length-1].start(); +o.#']}Pl
&~"N/o
Kj"n Id)
//等待子线程结束 p@$92> '
//int count = 0; o/U}G,|G
//是否结束while循环 mv<cyWp
boolean breakWhile = false; ?zo7.R-Vac
}m!T~XR</
pE1uD4lLb
while(!bStop) (>Sy,
{ 1\jj3Y'i'
write_nPos(); JpQV7}$
Utility.sleep(500); JWt@vf~
breakWhile = true; #,jm3Mqj
3&X5*-U
%*L8W*V
for(int i=0;i<nStartPos.length;i++) ,[n=PJVw/
{ zPvTRW~H\
if(!fileSplitterFetch.bDownOver) zll?/|%
{ kaZcYuT.9
breakWhile = false; b^Do[o}5
break; Dmtsu2o
} %)}_OXWf:
} 9dg+@FS}=
if(breakWhile) `=TJw,q
break; p=Qo92 NH
FN0<iL
*XXa9z
//count++; (Q"s;g
//if(count>4) .>5E 4^$%
// siteStop(); 7n#Mh-vq
} ipiS=
]{-ib:f~
Si;eBPFH
System.err.println("文件下载结束！"); kKQD$g.z6
} `C:J{`
catch(Exception e){e.printStackTrace ();} )q7!CG'oY
} ZYl*-i&~?
QswFISch
!&8B8jHqA
//获得文件长度 !;PKx]/&
public long getFileSize() 0@!-+}i
{ =rNI&K_<
int nFileLength = -1; &'5j!
try{ Yu9(qRK
URL url = new URL(siteInfoBean.getSSiteURL()); e58tf3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $+ \JT/eG9
httpConnection.setRequestProperty("User-Agent","NetFox"); ;;17 #T2
ds+0y;vc
=sXk,I;
int responseCode=httpConnection.getResponseCode(); ]gb?3a}A
if(responseCode>=400) uQkFFWS
{ [MM`#!K%
processErrorCode(responseCode); uY)|
return -2; //-2 represent access is error j&?@:Zg v
} 0bIhP,4&
q-0( Wx9|
CwzDkr&QC_
String sHeader; |A u+^#:;
$T'lWD*
/vPcg
for(int i=1;;i++) alQ:'K
{ ;x=0+0JD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7OZjLD{ID
//Utility.log(in.readLine()); \H?r[]*c%
sHeader=httpConnection.getHeaderFieldKey(i); a/ Z\h{*
if(sHeader!=null) {Ve_u
{ rcMSso2
if(sHeader.equals("Content-Length")) f,Dj@?3+
{ _$qH\>se
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LT '2446
break; &FzZpH
} #.W<[KZf
} ytGcigw(P
else ,dk!hm u
break; xCiq;FFR
} [lAZ)6E~=
} pj'[ H
catch(IOException e){e.printStackTrace ();} v+`gQXJ"G
catch(Exception e){e.printStackTrace ();} =I9RM9O<
7pz #%Hf
sZPA(N?
Utility.log(nFileLength); FAd4p9[Y
}7|UA%xz
$>PV6
return nFileLength; h.h\)>DM@
} |Xk>a7X
odpjEeQC
|`6*~ciUV
//保存下载信息（文件指针位置） H(j983
private void write_nPos() b\Gw|?Rv
{ DlbNW& V
try{ KdtQJ:_`k
output = new DataOutputStream(new FileOutputStream(tmpFile)); T|Fl$is
output.writeInt(nStartPos.length); lK3Z}e*eXQ
for(int i=0;i<nStartPos.length;i++) (E?X@d iu
{ m&8'O\$
// output.writeLong(nPos); ^NiS7)FX
output.writeLong(fileSplitterFetch.nStartPos); %FO#j6
output.writeLong(fileSplitterFetch.nEndPos); Tf?|*P
} 3It9|Y"6[
output.close(); &,~Oi(SX5
} aRF}FE,u
catch(IOException e){e.printStackTrace ();} ]eZrb%B.
catch(Exception e){e.printStackTrace ();} R<x~KJ11c
} :HQQ8uQfb
x.~AvJ
}0~4Z)?e3
//读取保存的下载信息（文件指针位置） 1|Z!8:&pj
private void read_nPos() .:=G=v=1
{ -mK;f$X
try{ EG[Rda
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i"o %Gc
int nCount = input.readInt(); &ywU^hBh
nStartPos = new long[nCount]; K.K=\ Y2
nEndPos = new long[nCount]; uMe]].04
for(int i=0;i<nStartPos.length;i++) DNl'}K1W
{ o&"nF+,
nStartPos = input.readLong(); e2l!L*[g
nEndPos = input.readLong(); xRM)f93@
} 1x~dsM;q
input.close(); %gE*x #
} 1MnT*w
catch(IOException e){e.printStackTrace ();} jou741
catch(Exception e){e.printStackTrace ();} a"&Gs/QKSC
} m3E`kW|
j>-O'CO
7[?{wbq
private void processErrorCode(int nErrorCode) "nEfk{g
{ qt!0#z8
System.err.println("Error Code : " + nErrorCode); Ryrvu1 k
} P4S]bPIp
YZ0Jei8+-
@is!VzE
//停止文件下载 [=q&5'FY0
public void siteStop() ^J-\s_)"
{ Tweku}D7
bStop = true; (TJ )Y7E
for(int i=0;i<nStartPos.length;i++) dGY:?mf&
fileSplitterFetch.splitterStop(); !O}^Y
^TF71uo
/I/gbmc)
} I c 2R\}q
} Z0I>PBL@l
//负责部分文件的抓取 ;Wu6f"+Y#
**FileSplitterFetch.java 8\{1y:|
*/ _gl7Ma
package NetFox; ^\ocH|D
~ '/Yp8(
1Vy8TV3D
import java.io.*; \DC0`
import java.net.*; tlJ@@v&=
--chU5
+1o4l i
public class FileSplitterFetch extends Thread { KrDG
#%$U-ti
A,;V|jv9
String sURL; //File URL M4`.[P4
long nStartPos; //File Snippet Start Position /l&$B
long nEndPos; //File Snippet End Position nA?Ks!9T
int nThreadID; //Thread's ID EYD24
boolean bDownOver = false; //Downing is over z[~ph/^
boolean bStop = false; //Stop identical gJC~$/2
FileAccessI fileAccessI = null; //File Access interface vlS+UFH0
3BzC'nplm
9`X}G`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b>Em~NMu_
{ :[C"}mR1
this.sURL = sURL; L.tW]43K
this.nStartPos = nStart; rZSD)I
this.nEndPos = nEnd; 0c6Ea>S[
nThreadID = id; GI _.[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }s++^uX6
} 6I!B>V#U+
g/f^|:
O-jpS?@
public void run() 3JJEj1O
{ t#BQB<GI
while(nStartPos < nEndPos && !bStop) UHT2a9rG
{ o;5ns
]u<8jr
)~[rb<:)b
try{ V|W[>/
URL url = new URL(sURL); cWS 0B $$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `+0K~k|DC
httpConnection.setRequestProperty("User-Agent","NetFox"); la}Xo0nq0+
String sProperty = "bytes="+nStartPos+"-"; BDiN*.w5
httpConnection.setRequestProperty("RANGE",sProperty); DO{Lj#@
Utility.log(sProperty); >Xv Fg
>#Ue`)d`aY
u]uZc~T
InputStream input = httpConnection.getInputStream(); RR9G$}WS(
//logResponseHead(httpConnection); ;\48Q;
xjK@Q1MJ
+ko-oZ7V
byte[] b = new byte[1024]; eWWtMnq
int nRead; )N'rYS'9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sRKoM
{ k|D =Q
nStartPos += fileAccessI.write(b,0,nRead); ,|G~PC8
//if(nThreadID == 1) I:Q3r"1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cfhiZ~."T
} _k O<|ev
\;bDDTM
J-d>#'Wb|
Utility.log("Thread " + nThreadID + " is over!"); *1c1XN<7
bDownOver = true; e61e|hoX\
//nPos = fileAccessI.write (b,0,nRead); q)rxv7Iu\
} ]7DS>%mY(
catch(Exception e){e.printStackTrace ();} Yx"un4
} KzWqHq
} gO%oA} !i
p|9Eue3j2
bTepTWv
//打印回应的头信息 .6HHUy
public void logResponseHead(HttpURLConnection con) $3)Z>p
{ e.VR9O]G
for(int i=1;;i++) q:ah%x[
{ s)9d\{
String header=con.getHeaderFieldKey(i); O~DdMW
if(header!=null) 6O\a\z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sX[k}=HCK
Utility.log(header+" : "+con.getHeaderField(header)); -a\[`JHi
else !}I+)@~\w
break; -?vII~a9y
} ]Mb:zs<r
} !&#5*
V<ExR@|}.%
Gk-49|qIV
public void splitterStop() y)uxj-G
{ hA:RVeS{
bStop = true; O0RV>Ml'&
} .{,fb
M T]2n{e
4D=^24f`0
} Aw"Y_S8.
`RHhc{
C7Ny-rj}IA
/* Gph:'3 *X
**FileAccess.java ?M9?GodbP.
*//文件访问(定位，写) JrNqS[c/
package NetFox; pKNrEq
import java.io.*; @5tGI U;1
BRTCo,i
KybrSa
public class FileAccessI implements Serializable{ \$W\[s4I
qW 2'?B3<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /7LAd_P6
RandomAccessFile oSavedFile; e]zd6{g[m
long nPos; ~ya@ YP]';
EK2mJCC|
Aq;WQyZ2
public FileAccessI() throws IOException 'y%*W:O
{ sg%Ptp
this("",0); N:~CN1
} SL5QhP
fjh,e
we&D"V
public FileAccessI(String sName,long nPos) throws IOException cH6<'W{*
{ a?1Ml>R6P
oSavedFile = new RandomAccessFile(sName,"rw"); 'bn$"A"{o
this.nPos = nPos; p-f"4vH
oSavedFile.seek(nPos); 'n/L1Fn
} D]'/5]~z<
rcUJOI
$A^OP{
public synchronized int write(byte[] b,int nStart,int nLen) %4^NX@1jV
{ |3P dlIbO
int n = -1; 0P l>k'9
try{ 7p_B?r
oSavedFile.write(b,nStart,nLen); ;!pSYcT,
n = nLen; 4_W*LG~2s
} )MeeF-Ad6
catch(IOException e) O#n=mJ
{ dM)x|b3z
e.printStackTrace (); Ef\&3TcQ
} L]wk Ba
\\Te\l|L
YckLz01jh
return n; )R6-]TkA_
} $0&<Jx
s_ %LU:WC
a_(T9pr
} iyTKy+3A
yn|U<Hxl~H
@M!nAQ8hY
/* @&f~#Xe
**SiteInfoBean.java E-v^eMWX
*/ Jxsch\
package NetFox; |Ng}ZLBM
RC~C}
E~ +g6YlT
public class SiteInfoBean { ub9,Wd"^
EI8KKo *
:=?od 0]W
private String sSiteURL; //Site's URL 9s&dN
private String sFilePath; //Saved File's Path MeDlsO
private String sFileName; //Saved File's Name CPci 'SO
private int nSplitter; //Count of Splited Downloading File MnTqWC90
!0X/^Xv@=
#b>D^=NV>)
public SiteInfoBean() tvcM< e20
{//nSplitter的缺省值为5 D]?yGI_
//default value of nSplitter is 5 F*p@hl
this("","","",5); mWTV)z57
} dmPAPCm%y
1otE:bi
UId?a}J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?)2;W
{ f0"_ {\
sSiteURL= sURL; K;*B$2Z#k
sFilePath = sPath; [7Liken
sFileName = sName; KJi8LM
this.nSplitter = nSpiltter; .f9&.H#
j5!pS xOC
`%_(_%K
} h~5gHx/a
r1[#_A`Yn
Odr<fvV,>
public String getSSiteURL() 8+Abw)]s
{ 46D_K
return sSiteURL; =)f5JwZPG
} 6r)B|~,OA
yX%NFXD
Oid;s!-S6
public void setSSiteURL(String value) O #5`mo
{ r#NR3_@9
sSiteURL = value; ~(}nd
} +Uxtxl'
an)Z.x
F7\nG}#s
public String getSFilePath() }BAe
{ C4K"eX,K
return sFilePath; V-ONC
} ;^ff35EE8
$GQ{Ai:VwF
/>O.U?
public void setSFilePath(String value) iQvqifDmh
{ M3s:B& /
sFilePath = value; "c*#ZP
} 0}9
#Yx /ubg6
"ZP)[ [Rd
public String getSFileName() R'$1,ie
{ |?\2F
return sFileName; XGAR8=tic
} uQ3W =
Ygc.0VKMR
8Ud.}< Zi
public void setSFileName(String value) Q1RUmIe_&
{ KouIzWf.
sFileName = value; H](TSt<Q"
} 2#@-t{\3-p
3j\Py'};
!RwMUnp
public int getNSplitter() Dv}VmC""
{ i2?TMM!Fe
return nSplitter; $d Nmq
} }b+$S'`Bv
3w8v.J8q
K_-S`-eH
public void setNSplitter(int nCount) dG)}H_
{ &{S@v9~IT
nSplitter = nCount; b q8nV
} ,"Nb;Yhg
} wLKC6@ W
QJ,~K&?
U]"6KS
/* t:%u4\nZ;
**Utility.java qU^`fIa
*/ ' pfkbmJ
package NetFox; },,K6*P
@Uqcym.
NW~`oc)NS
public class Utility { UVD*GsBk
yH(%*-S
e/zz.cd){
public Utility() $u, ~183
{ < ;fI*km
+@MG$*}Oz
Yq%r\[%*
} Ur(< ]
%8lWJwb7u
//线程睡眠 |z`AIScT
public static void sleep(int nSecond) QxiAC>%K
{ t]+h.
try{ vlPViHF.
Thread.sleep(nSecond); UxvT|~"
} =W"9a\m
catch(Exception e) cD9.L
{ qjH/E6GGg
e.printStackTrace (); HJ!P]X_J1
} WnQ+
} ?-=<7 ~$
w%~Mg3|
//日志 G3gEL)b*
public static void log(String sMsg) d+]/0J!c
{ n8o(>?Kw
System.err.println(sMsg); e84O 6K6o
} y)T|1)
G`z=qaj
' [%?j?2r
public static void log(int sMsg) ( c +M"s
{ Iy@6cd,)S
System.err.println(sMsg); )@6iQ
} w5q'M
} PDpDkcy|QM
_.5ABE
dQI6.$?
/* ^@;P-0Sy
**TestMethod.java R?8/qGSVqJ
*/ nQd~i0`vB
package NetFox; 3e1^r_YI
T*rz#O
S{UEV7d:n0
public class TestMethod { M+WN\.2pX
gNSsT])
#{zF~/Qq
public TestMethod() +[Q`I*C
{ ///xx/weblogic60b2_win.exe uOb}R
try{ Z+ )<FX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -Hg,:re2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V(F1i%9lg
SiteFileFetch fileFetch = new SiteFileFetch(bean); YRU#/TP
fileFetch.start(); _s+_M+@et
} cfL:#IM
catch(Exception e){e.printStackTrace ();} b#Vm;6BHD1
) -@Dh6F
#g]eDU-[
} hv)d
mf\@vI
] jycg@=B
public static void main(String[] args) vzZ"TSP
{ 6IKi*}
new TestMethod(); =6[R,{|C
} ]GXE2A_i;
} PGA `R
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