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)); }&6:0l$4!
} hK{<&T
for(int i=0;i<nEndPos.length-1;i++) fuF{8-ua
{ (#z6w#CU(
nEndPos = nStartPos[i+1]; ^7;s4q
} $2}%3{<j
nEndPos[nEndPos.length-1] = nFileLength; EUV8H}d5
} &=:3/;c
} ZYt<O
gMPp'^g]_
YZtd IG
//启动子线程 M&Ln'BC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n:1Ijh 1
for(int i=0;i<nStartPos.length;i++) e VQ-?DK
{ }*qj,8-9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pDvznpQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AA=eWg
nStartPos,nEndPos,i); Y"m(hs$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 91q
fileSplitterFetch.start(); HGd.meQ
} 0plX"NU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F>X<=YO0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pe3;pRh'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ),xD5~_=q
nEndPos = " + nFileLength); &"J;
// fileSplitterFetch[nPos.length-1].start(); wg\p&avvb
\ptjnwC^O
SN\c2^#
//等待子线程结束 0O*kC43E_
//int count = 0; p7r/`_'|
//是否结束while循环 qn |~YXn
boolean breakWhile = false; cKoW5e|u
@tD (<*f+
m_`%#$s}
while(!bStop) 'lu3BQvfh
{ )Z['=+s%
write_nPos(); _G25$%/LU
Utility.sleep(500); E7aG&K
breakWhile = true; n"Bc2}{
:rjfAe=s
apfr>L3
for(int i=0;i<nStartPos.length;i++) vP? T
{ ~gNFcJuy
if(!fileSplitterFetch.bDownOver) +"k?G
{ rcY &n^:
breakWhile = false; l~DIV$>,Z
break; _jgtZ
} $7i[7S4
} 3Z&!zSK^
if(breakWhile) FC+h \
break; #reW)P>
@';.$
Aq3\Q>klH)
//count++; &Vgpv#&Cfx
//if(count>4) g0B%3v
// siteStop(); @>V;guJC%
} DZ`m{l3H
YgS,5::SU
<c!gg7@pm
System.err.println("文件下载结束！"); Q {BA`Q@V
} jF/S2Ty2
catch(Exception e){e.printStackTrace ();} 8]R{5RGy
} n5^57[(
_5x]BH6f
Ude?[6
//获得文件长度 p?4[nS-,
public long getFileSize() tAI v+L
{ +"=ydF.9
int nFileLength = -1; A=p'`]Yld
try{ \4C[<Gbx$(
URL url = new URL(siteInfoBean.getSSiteURL()); 4neO$^i8J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ek6g?rj_
httpConnection.setRequestProperty("User-Agent","NetFox"); xk7Dx}
*kYGXT,f]
N#t`ZC&m'
int responseCode=httpConnection.getResponseCode(); MtN!Xx
if(responseCode>=400) D3P/: 4
{ t4/ye>P &
processErrorCode(responseCode); }<l:~-y|
return -2; //-2 represent access is error !@N?0@$/
} uN>5Eh&=Pf
h8(>$A-
PwthYy
String sHeader; 0\B{~1(^
0_MtmmL.
d%-/U!z?
for(int i=1;;i++) %d(= >
{ 8"ZS|^#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .5}Gt>4XM
//Utility.log(in.readLine()); 57gt"f
sHeader=httpConnection.getHeaderFieldKey(i); 4K? \5(b
if(sHeader!=null) JPng !tvR
{ 8UqH"^9.Q7
if(sHeader.equals("Content-Length")) c%gL3kOT
{ Qr4 D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bcpsjUiy#
break; 5I^;v;F
} `M 'tuQ M
} ~ A=Gra
else @7C.0>W_A
break; N~l*//Ep
} P*~ vWYH9
} AovBKB $
catch(IOException e){e.printStackTrace ();} zp<B,Ls
catch(Exception e){e.printStackTrace ();} vlE]RB
7}6CUo
ms&1P
Utility.log(nFileLength); 0H_uxkB~
A1,q3<<D%
0BhcXHt
return nFileLength; _6ck@
} c1jRj=\
LCtVM70
_N^w5EBC]
//保存下载信息（文件指针位置） -C3[:g
private void write_nPos() 6l;2kztGp
{ DF4CB#
try{ @p WN5VL
output = new DataOutputStream(new FileOutputStream(tmpFile)); {B4qeG5
output.writeInt(nStartPos.length); g3>>gu#0DC
for(int i=0;i<nStartPos.length;i++) hd~#I<8;2
{ vO~Tx
// output.writeLong(nPos); CEc(2q+%i
output.writeLong(fileSplitterFetch.nStartPos); ]77f`<q<}!
output.writeLong(fileSplitterFetch.nEndPos); [WG\wj.
} *qk7e[IP
output.close(); liH#=C8l*%
} 'Kbrz
catch(IOException e){e.printStackTrace ();} wL="p) TO.
catch(Exception e){e.printStackTrace ();} t&J A1|q
} QDJ "X
>Bf3X&uS
LSJ.pBl\X
//读取保存的下载信息（文件指针位置） cGgfCF^`
private void read_nPos() c$7~EP
{ 'xxM0Kn`
try{ Z_m<x!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YI,t{Wy
int nCount = input.readInt(); tzIP4CR~F&
nStartPos = new long[nCount]; 111A e*U
nEndPos = new long[nCount]; 5:f!EMb
for(int i=0;i<nStartPos.length;i++) 4^bt~{}
{ f'@ L|&w
nStartPos = input.readLong(); 2tpuv(H;
nEndPos = input.readLong(); C)EP;5k'!\
} M>p<1`t-&
input.close(); It&CM,=t
} vB_3lAJt@
catch(IOException e){e.printStackTrace ();} d-+jb<C&
catch(Exception e){e.printStackTrace ();} $m2#oI'D
} 2J&~b8:
>WDHRC
kexV~Q
private void processErrorCode(int nErrorCode) Y'iyfnk
{ Xi[]8o
System.err.println("Error Code : " + nErrorCode); n>j2$m1[
} Q/ .LDye8
j_N<aX
j7kX"nz
//停止文件下载 kF~(B]W(
public void siteStop() V@k+RniEO
{ .G!xcQ`?
bStop = true; 6Uk+a=Ar
for(int i=0;i<nStartPos.length;i++) 7`;sX?R
fileSplitterFetch.splitterStop(); W wPzm?30
*0!p_Hco
Hf]:mhH
} :#^qn|{e
} u5k{.&
//负责部分文件的抓取 L4m Vk
**FileSplitterFetch.java `HXv_9
*/ zH}3J}
package NetFox; 5buW\_G)
D~ Y6%9
n*wQgC'vw
import java.io.*; ra T9
import java.net.*; BL16?&RK
4F#H$`:[
%(/E `
public class FileSplitterFetch extends Thread { -?)^ hbr
',0:/jSz
m.Zy$SDj(
String sURL; //File URL y2#>a8SRS
long nStartPos; //File Snippet Start Position nJN-U+)u
long nEndPos; //File Snippet End Position dnoF)(d&Cm
int nThreadID; //Thread's ID K!&W}_@l
boolean bDownOver = false; //Downing is over z0<E3t
boolean bStop = false; //Stop identical nZ(]WPIN"
FileAccessI fileAccessI = null; //File Access interface BKg8p]`+
.s*N1 U?h
F8?2+w@P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x'x5tg
{ xj>P5\mW#
this.sURL = sURL; fe/;U=te
this.nStartPos = nStart; .b3h?R*&
this.nEndPos = nEnd; ,X^3.ILz
nThreadID = id; 8O'bCBhv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >80k5$t
} 3d6z_Yd:
ITw *m3
:kR>wX
public void run() c#{lXS^
{ =6Ok4Z
while(nStartPos < nEndPos && !bStop) iF^qbh%%E
{ ^:{8z;w!(
xX%ppD7
\(i'iC
try{ l[$GOLeS
URL url = new URL(sURL); lfHN_fE>Mq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7s?#y=M
httpConnection.setRequestProperty("User-Agent","NetFox"); 7! >0
String sProperty = "bytes="+nStartPos+"-"; FAdTm#tgW]
httpConnection.setRequestProperty("RANGE",sProperty); . fja;aG
Utility.log(sProperty); wBXa;.
M\m:H3[
`CS\"|z
InputStream input = httpConnection.getInputStream(); FE!jN-#
//logResponseHead(httpConnection); GLtWo+g0
{q)d
H_RfIX)X
byte[] b = new byte[1024]; gvuv>A}vJ
int nRead; %(W&(eN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8)1q,[:M
{ SPb+H19;
nStartPos += fileAccessI.write(b,0,nRead); 0* F` h
//if(nThreadID == 1) f X[xZGV,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E,Rj;?
} UF!qp
d*d:-f~q
3O2G+G2
Utility.log("Thread " + nThreadID + " is over!"); /=p[k^A
bDownOver = true; ]H !ru
//nPos = fileAccessI.write (b,0,nRead); 940:NOgm
} DH?n~qKpC
catch(Exception e){e.printStackTrace ();} i;1pw_K
} c1k[)O~
} nKm# kb
0 MK}
$\NqD:fgb
//打印回应的头信息 MWv@]P_0p!
public void logResponseHead(HttpURLConnection con) yk8b>.Y\A
{ Ljm`KE\Q;t
for(int i=1;;i++) `#ruZM066
{ D;> 7y}\
String header=con.getHeaderFieldKey(i); 'z8FU~oU
if(header!=null) t,fec>.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uM`i!7}
Utility.log(header+" : "+con.getHeaderField(header)); dBd7#V:}yV
else )ovAGO
break; JI.=y5I
} 6NX#=A
} Gf"TI:xa
i4|R0>b
\lQ3j8U
public void splitterStop() bIiuna\
{ y{@\8B]
bStop = true; oM!&S'M/
} e|{R2z"^
?2&= +QaT
dHIk3j-!
} ,N(Yjq"R
nnj<k5
H7tviSTd
/* jvB[bS`<H
**FileAccess.java U)8yd,qG[%
*//文件访问(定位，写) .m]}Ba}J$
package NetFox; pZ>yBY?R8>
import java.io.*; [o<hQ`&
v>wN O
!4afU:
public class FileAccessI implements Serializable{ -NJpql{Cb
t/;0/ql\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |qMG@
RandomAccessFile oSavedFile; I #1~CbR
long nPos; i1uoYb?4(I
*Mhirz%iD
~".@mubt1$
public FileAccessI() throws IOException I.3~ctzu
{ V,rc&97
this("",0); -E?:W`!
} o^~ZXF}
@[J6JT*E
*,Bm:F<m
public FileAccessI(String sName,long nPos) throws IOException T$lV+[7
{ .+1I>L
oSavedFile = new RandomAccessFile(sName,"rw"); #sc!H4
this.nPos = nPos; !*:g??[T
oSavedFile.seek(nPos); c7r(&h
} 06]3+s{{
E'aOHSAg
X\Bl? F
public synchronized int write(byte[] b,int nStart,int nLen) .hmeP MK
{ Ts !g=F
int n = -1; aPelt`
try{ gw"cXny
oSavedFile.write(b,nStart,nLen); Cy?]o?_?
n = nLen; 1]:,Xa+|S
} tG$O[f@U6
catch(IOException e) [gBf1,bK
{ 2%WeB/)9
e.printStackTrace (); &"%Ws{Qn]
} 7=Muq]j2
h,Hr0^?
:o!Kz`J
return n; X0 |U?Ib?
} /#Pm'i>B
u9@B&
{*O%A
} 0FcDO5ia
vSnVq>-q&
CBd%}il
/* &tZIWV1&
**SiteInfoBean.java v<v;ZR)
*/ }3: mn
package NetFox; W$`v^1M2o
<)TIj6
.rk5u4yK
public class SiteInfoBean { c]Epg)E
&)k=ccm
73X*|g[O
private String sSiteURL; //Site's URL ^}~Q(ji7
private String sFilePath; //Saved File's Path hOB<6Tm[
private String sFileName; //Saved File's Name <}WSYK,zUY
private int nSplitter; //Count of Splited Downloading File e^eJ!~0
t}R!i-D|HB
8j>V?'Szk
public SiteInfoBean() S} UYkns*
{//nSplitter的缺省值为5 1!^BcrG.
//default value of nSplitter is 5 #tKks:eL
this("","","",5); :'bZ:J>f
} /}@F q
zY\u" '4
PFp!T [)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IQ<G.
{ Sk53Lc
sSiteURL= sURL; bQ>wyA+G&E
sFilePath = sPath; %EU_OS(u.{
sFileName = sName; F8?,}5j
this.nSplitter = nSpiltter; f0g/`j@Up
n@+?tYk*e
.eIs$
} g5|&6+t.
"m^gCN}c
qe&|6M!
public String getSSiteURL() '|]}f}Go
{ M%_*vD
return sSiteURL; !f(A9V
} 7kV$O(4
oA5Qk3b:
5b rM..
public void setSSiteURL(String value) B`QF;,3S
{ OF<:BaRs/
sSiteURL = value; d"n>Q Tn\
} PV,Z@qm@^
0E#??gN
BaIpX<$T
public String getSFilePath() nq?+b >//
{ RTVU3fw
return sFilePath; 4Vi*Qa_,y
} =b$g_+
7Z2D}O+
w aniCEo
public void setSFilePath(String value) m)66g]F+
{ Z]Xa:[
sFilePath = value; qGag{E5!
} YL*FjpVW
>A D!)&c
e-`9-U%6
public String getSFileName() /{buFX2"}
{ yI8O#
return sFileName; @XG1d)sE
} eHUyV@
{s@!N
`Zuo`GP*1
public void setSFileName(String value) Bs0~P 4^
{ i +@avoW
sFileName = value; 4}D&=0IZ
} w;@v#<q6
by9UwM=gp
J37vA zK%
public int getNSplitter() pm+E)z6Yo
{ / P@P1l|I
return nSplitter; Uot(3p!S6
} \68bXY.
_lI(!tj(
8Q/cJ+&
public void setNSplitter(int nCount) 4?@5JpC9VA
{ $o+@}B0)
nSplitter = nCount; ^4WZ%J#g
} A?HDY_u
} ksU& q%1
9u=]D> kb
JT}"CuC
/* x!I@cP#O
**Utility.java ){/n7*#Th%
*/ t_I-6`8o]
package NetFox; nZj&Ma7R
pDP* 3
rk=w~IZJ3
public class Utility { OkQ< Sc
b/.EA'/
=Cf@!wZ^
public Utility() XU"G
{ |oeg'T
UBv#z&@[
H '5zl^8I
} -"yma_
/tkV/
//线程睡眠 .vmCKZ
public static void sleep(int nSecond) i`9}">7v~
{ -;Mh|!yg
try{ 0p3) t
Thread.sleep(nSecond); hT=E~|O
} O:V.;q2]U
catch(Exception e) &Kc45
{ %QDAog
e.printStackTrace (); }}Q h_(
} _JpTHpqu
} G|&$/]~
[Ketg
//日志 agoMsxI9
public static void log(String sMsg) F$v^S+Ch
{ cPL6(&7
System.err.println(sMsg); l}S96B
} sFk{Tv@Yz
'u PI~l`g
fCb&$oRr!
public static void log(int sMsg) ]$)};8;7W
{ 1iqgTi>
System.err.println(sMsg); vEt=enQ
} aQWg?,Ju6
} 5#_GuL%
V+'zuX
!Y^B{bh
/* "5,Cy3
**TestMethod.java , Z1 &MuV
*/ rIv#YqT
package NetFox; F9_X^#%L
z5^Se!`5
a#Z#-y!
public class TestMethod { \ 511?ik
k fOd|-
vKbGG
public TestMethod() :d<F7`k H
{ ///xx/weblogic60b2_win.exe yF XPY=EQ
try{ t]t(/x#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3gCP?%R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Kv5 !cll5
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^7kYG7/
fileFetch.start(); ]nS9taEA
} PVq y\i
catch(Exception e){e.printStackTrace ();} pkIJbI{aS
&fxyY(
sBN4:8
} ]x_14$rk
oe_,q&e
NUY sQO)
public static void main(String[] args) I7#+B1t
{ >va9*pdJ
new TestMethod(); OYfP!,+bn
} ui*CA^ Y
} "y .(E7 6
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