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)); 95hdQ<W
} IltU6=]"l
for(int i=0;i<nEndPos.length-1;i++) jK-usn
{ @sLB _f
nEndPos = nStartPos[i+1]; DyPb]Udb:
} QN OA66
nEndPos[nEndPos.length-1] = nFileLength; K{[N.dX(
} Xo~kB)|,
} pQ9~^
A!fRpN
TrmrA$5f
//启动子线程 WTQd}f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <<[\ Rv
for(int i=0;i<nStartPos.length;i++) -JfO} DRI
{ [eO6H2@=z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XZ[3v9?&n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [Cf{2WB:7
nStartPos,nEndPos,i); >19j_[n@VC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V( SRw
fileSplitterFetch.start(); l6k.`1.In
} N2e]S8-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P~7p~ke
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (`FY{]Wz!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", - {|
nEndPos = " + nFileLength); &Y|AX2KUC
// fileSplitterFetch[nPos.length-1].start(); EK<ly"S.
NGOyd1$7N
?D S|vCae
//等待子线程结束 2kVQ#JyuRI
//int count = 0; hxx`f-#=
//是否结束while循环 oiNt'HQ2/
boolean breakWhile = false; V}+Ui]ie|I
#JW~&;
(GXFPEH8
while(!bStop) T$Rj/u t1
{ K1[(%<Gp
write_nPos(); !S5_+.U#
Utility.sleep(500); 2;&!]2vo$
breakWhile = true; A_JNj8<6r
w>uo-88
V{yk
for(int i=0;i<nStartPos.length;i++) F=r`'\JV[
{ f4r)g2Zb[
if(!fileSplitterFetch.bDownOver) h^=9R6im
{ RqRyZ*n
breakWhile = false; +DA,|~k_
break; R1NwtnS
} &1$|KbmV4
} 7bC)Co#:
if(breakWhile) { K*
break; 9>hK4&m^
TxXX}6
m. "T3K
//count++; El4SL'E@
//if(count>4) BhC>G2 ^7
// siteStop(); P1A5Qq
} C!s !j
w^wh|'u^_@
J^)=8cy
System.err.println("文件下载结束！"); "=vH,_"Ql
} y?.l9
catch(Exception e){e.printStackTrace ();} NB?y/v
} z{ MO~d9
yjj)+eJ(Q
$|pD}
//获得文件长度 )G=hgqy
public long getFileSize() w-?|6I}T
{ ua]?D2
int nFileLength = -1; ry!0~ir
try{ zaMKwv}BR
URL url = new URL(siteInfoBean.getSSiteURL()); YH/3N(],
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VAet!H+]
httpConnection.setRequestProperty("User-Agent","NetFox"); yy#4DYht
APM!xX=N
2}jC%jR2
int responseCode=httpConnection.getResponseCode(); xI(Y}>
if(responseCode>=400) *#g[ jl4
{ Ft^+P*
processErrorCode(responseCode); \:|"qk
return -2; //-2 represent access is error @w{"6xc%a
} o0\d`0-el
2V)qnMxAZJ
"Iwd-#;$;
String sHeader; i*2l4
~fR-cXj"
UhVJ!NrT
for(int i=1;;i++) Xw |6 #^
{ *J|]E(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aYd`E4S+
//Utility.log(in.readLine()); kcyT#'=j
sHeader=httpConnection.getHeaderFieldKey(i); X;%*+xQ^
if(sHeader!=null) V.^Z)iNf^
{ GG$&=.$
if(sHeader.equals("Content-Length")) V/W{d[86G
{ 0$\ j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I4\ c+f9
break; Qa-~x8]
} E{W(5.kb;i
} ]?A-D,!(
else F uJ=]T
break; SJXP}JB_
} Mv#\+|p 1x
} :1,xse
catch(IOException e){e.printStackTrace ();} wS}Rl}#Oh?
catch(Exception e){e.printStackTrace ();} TU}./b@F
8PtX@s43\
I4%25=0?
Utility.log(nFileLength); ]#t5e>o|
p4M7BK:nf
`;H3['~$
return nFileLength; iyr'9BA
} 3JcI}w
TSHH=`cx
Z&Ao;=Gp1
//保存下载信息（文件指针位置） A!.* eIV|
private void write_nPos() xA {1XS}
{ )!jX$bK
try{ &p6^
output = new DataOutputStream(new FileOutputStream(tmpFile)); +U= !svE
output.writeInt(nStartPos.length); RuuXDuu:VL
for(int i=0;i<nStartPos.length;i++) Zg~6
{ #;~dA
// output.writeLong(nPos); &RbT&
output.writeLong(fileSplitterFetch.nStartPos); 'Bb@K[=s
output.writeLong(fileSplitterFetch.nEndPos); l5fF.A7TT
} F}dq~QCzw
output.close(); $mZpX:7/u8
} CY i{WV(:
catch(IOException e){e.printStackTrace ();} bf&k:.v'8
catch(Exception e){e.printStackTrace ();} c`x[C
} /!HFi>
4,P!D3SH
StWF66u34&
//读取保存的下载信息（文件指针位置） IWD21lS
private void read_nPos() TVEFZ\p<A
{ Y~+`F5xX<
try{ F\(7B#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;1[Lwnm
int nCount = input.readInt(); k}r)I.Lp
nStartPos = new long[nCount]; 9HJA:k*k|
nEndPos = new long[nCount]; 8w]>SEGFs
for(int i=0;i<nStartPos.length;i++) R4P$zB_<2
{ DA-W =Cc
nStartPos = input.readLong(); O| zLD
nEndPos = input.readLong(); /aHx'TG
} 5'hQ6i8
input.close(); wc7F45l4
} Q]NGd 0J
catch(IOException e){e.printStackTrace ();} ^tY$pPA
catch(Exception e){e.printStackTrace ();} 96.Vm*/7
} 2*1FW v
D|rcSa.M
<"rckPv_H
private void processErrorCode(int nErrorCode) kx_PMpc
{ i1JWdHt
System.err.println("Error Code : " + nErrorCode); jXALN
} dgsD~.((A
X*Dt<i};v
gdVajOAu
//停止文件下载 GtNGrJU
public void siteStop() `.8#q^
{ k9iXVYQ.;r
bStop = true; *N|s+
for(int i=0;i<nStartPos.length;i++) y/}ENUGR
fileSplitterFetch.splitterStop(); a{%]X(';
Y^P'slY{%
b/g"ws_
} ]psx\ZMa
} e:H9!
//负责部分文件的抓取 UZq1qn@+
**FileSplitterFetch.java jQ[M4)>_k`
*/ +HxL>\
package NetFox; Wr+1G 8
RIQw+RG>
,)JSXo
import java.io.*; 2r~&+0sBP
import java.net.*; =-GHs$u%f
N2_9V~!
YDMimis\H5
public class FileSplitterFetch extends Thread { Jxy94y*
b 7%O[
N>J"^GX
String sURL; //File URL ]A2l%V_7
long nStartPos; //File Snippet Start Position zrJ/Fs+s
long nEndPos; //File Snippet End Position |vY0[#E8&
int nThreadID; //Thread's ID s*0PJ\E2
boolean bDownOver = false; //Downing is over }|7y.*
boolean bStop = false; //Stop identical i`2X[kc
FileAccessI fileAccessI = null; //File Access interface |,wp@)e6h
vHz]-Q-|9
30Z RKrW"~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8Qg,UX
{ )|@ H#kv?
this.sURL = sURL; [# '38
this.nStartPos = nStart; @]0;aZ{3
this.nEndPos = nEnd; B "z`X!\
nThreadID = id; C'c9AoE5>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p#Vh[UTl^
} HX3R@^vo
<Y9xHn&
Q/,jv5
public void run() 79svlq=
{ W l+[{#
while(nStartPos < nEndPos && !bStop) uKcwVEu
{ #+- /0{HT
Aey*n=V4#F
Evn=3Tw
try{ :uD*Q/
URL url = new URL(sURL); Vp'Zm:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :2KLziO2
httpConnection.setRequestProperty("User-Agent","NetFox"); >_4Ck{^d#
String sProperty = "bytes="+nStartPos+"-"; ?T(>!m
httpConnection.setRequestProperty("RANGE",sProperty); u0@i3Po
Utility.log(sProperty); ZE*m;
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hF!t{ Lf3
InputStream input = httpConnection.getInputStream(); !P&F6ViO=
//logResponseHead(httpConnection); !)(c_ uz
%`P6a38j
hK,e<?N^
byte[] b = new byte[1024]; m"<Sb,"x!
int nRead; ORV~F0d<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SJtQK-%wK>
{ |@x^5Ab$T
nStartPos += fileAccessI.write(b,0,nRead); 0 7CufoI
//if(nThreadID == 1) |-HV@c]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5;5DEMe
} ]i-peBxw
`;ofQz4
p. eq N
Utility.log("Thread " + nThreadID + " is over!"); 3f2%+2Zjt,
bDownOver = true; ERO'{nT&
//nPos = fileAccessI.write (b,0,nRead); )5}=^aqd
} W -Yv0n3
catch(Exception e){e.printStackTrace ();} g{zvks~it
} D~~&e<v'1
} ]{r*Z6bs
|=^p`CT
@{_L38. Nw
//打印回应的头信息 zoV4Gl
public void logResponseHead(HttpURLConnection con) P,x'1`k~
{ TX96 ^EoH
for(int i=1;;i++) ZxmMw
{ Zz<k^
String header=con.getHeaderFieldKey(i); hpD\,
if(header!=null) y\DR,$Py
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hE41$9?TJ
Utility.log(header+" : "+con.getHeaderField(header)); F_9eju^|
else El;\#la
break; BULf@8~(
} (cX;a/BR
} k !S0-/h
=/Ob kVYf
DD3.el}6a
public void splitterStop() wo($7'.@
{ c/Fy1Lv\
bStop = true; l,n0=Ew
} jP?YV
T5; zgr
)~{T
} QxRT%;'Zh]
\Kp!G1?_AY
lWr{v\L'
/* $TON`+lB
**FileAccess.java qB57w:J
*//文件访问(定位，写) raL!}
package NetFox; =.=4P~T&
import java.io.*; V _(L/6
Lo^0VD!O
Yv?nw-HM
public class FileAccessI implements Serializable{ '->%b
>h^CC*&'pw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u^DfRd&P0
RandomAccessFile oSavedFile; yrp5\k*{y
long nPos; hk =nXv2M
D#ZzhHHP
;GW[Yw>Rz
public FileAccessI() throws IOException O)y|G%O
{ J<g$hk
this("",0); !^{0vFWE
} D00I!D16
B?BB
m0}Pq{g
public FileAccessI(String sName,long nPos) throws IOException B$R"Ntp
{ {E6M_qZ
oSavedFile = new RandomAccessFile(sName,"rw"); xbbQ)sH&m
this.nPos = nPos; y0!-].5UH
oSavedFile.seek(nPos); d5zv8?|X+
} snPM&
xq`mo
OF[y$<jM
public synchronized int write(byte[] b,int nStart,int nLen) MKqMH,O
{ T5* t~`bfU
int n = -1; !S0$W?*
try{ K4\{G
oSavedFile.write(b,nStart,nLen); 7jss3^.wA
n = nLen; dQX<X}
} 5*M3sN
catch(IOException e) >?-etl
{ x$:>W3?T=^
e.printStackTrace (); C`qo
} #&fi[|%X$
uw!w}1Y]}2
J7Z`wjX1
return n; L5(7;
} RO>3U2
uY{zZ4iw
5c(mgEvq
} Un[olp
s"hSn_m
W6~aL\[
/* e70#"~gt[
**SiteInfoBean.java _ELuQ>zM]+
*/ MIV<"A
package NetFox; L="ipM:Z
h(M_ K
^^q9+0@
public class SiteInfoBean { U/hf?T;
.[%^~q7
UH8q:jOi
private String sSiteURL; //Site's URL Y[_{tS#u
private String sFilePath; //Saved File's Path pD^7ZE6
private String sFileName; //Saved File's Name WJ%4IaT
private int nSplitter; //Count of Splited Downloading File ,]A|z ~q
DC9\Sp?
<1t.f}}uX
public SiteInfoBean() T0:%,o
{//nSplitter的缺省值为5 I&2)@Zw
//default value of nSplitter is 5 }XOTK^YA
this("","","",5); C)x>/Qr~
} 47S1mxur
^("23mhfJ
7T\LYDT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gu~JB
{ rM?O2n
sSiteURL= sURL; v'0WE
sFilePath = sPath; 9'$\GN{0
sFileName = sName; 0m3:!#\
this.nSplitter = nSpiltter; mP!=&u fcU
kGz0`8URu
s5`CV$bz
} !hMD>B2Z
eo#2n8I>=1
j{8;5 ?x
public String getSSiteURL() !?AgAsSmc
{ U?@ s`.
return sSiteURL; FfeX;pi
} D8OW|wVE
71S~*"O0f
<0EVq8h
public void setSSiteURL(String value) *5e"suS2
{ UyFvj4SU
sSiteURL = value; g2Hz[C(
} A7`+XqG
2F}D?]A
ec8iZ8h8
public String getSFilePath() n]%T>\gw
{ 5`_UIYcI
return sFilePath; ''Pu
} U4$}8~o4
TnuaP'xZ
g!QX#_~Il
public void setSFilePath(String value) Kia34 ~W
{ =&_Y=>rA]0
sFilePath = value; A$JL"~R
} .RazjXAY
j7(S=
EPd9'9S
public String getSFileName() rtjUHhF
{ s%bm1$}
return sFileName; k<Y}BvAYB
} _?}[7K!~d
R!+_mPb=Q*
-XJXl}M.
public void setSFileName(String value) a<E\9DL
{ M~?2g.o'D
sFileName = value; jqzG=/0~{
} 6"o,)e/z
De<kkR{4
,(;TV_@$
public int getNSplitter() 8wf[*6VwV
{ kndN} Vq
return nSplitter; PHxU6UPqy
} (kYwD
J<9;Ix8R
ov 'g'1}
public void setNSplitter(int nCount) >h Rq
{ t}Q PPp y
nSplitter = nCount; \yE*nZ
} &6@#W]_
} zObrp
#0*oj/
JS!`eO/8
/* -"CXBKHb
**Utility.java E,}(jAq7
*/ %a=^T?8
package NetFox; it.'.aK4
b(HbwOt~3
K ; eR)
public class Utility { Y00hc8<
"y7IH GJ\3
%.rVIc"
public Utility() .4cVX|T
{ C"*8bVx]$n
?*/1J~<(@
9F"^MzZ
} my}l?S[2d@
t_"]n*zk1
//线程睡眠 L; o$vI~U,
public static void sleep(int nSecond) 1$S`>M%a
{ 2v\<MrL
try{ H/^t]bg,
Thread.sleep(nSecond); sK/Z'h{|
} Qn!KL0w
catch(Exception e) khb/"VYd
{ t%fcp
e.printStackTrace (); (7*((
} haSC[[o=
} ]Vm:iF#5P
"nA~/t=
//日志 8dUP_t~d#q
public static void log(String sMsg) OnND(YiX
{ 2EC<8}CG
System.err.println(sMsg); B1k;!@@14
} }8Yu"P${Y
V6!1(|
`L m9!?
public static void log(int sMsg) 'E)g )@^
{ i`7(5L~`
System.err.println(sMsg); v\G+t2{
} |ERf3
} VUUE2k;^
o^3X5})sv
v/GZByco>
/* iOdk)
**TestMethod.java M`49ydh&
*/ O"ebrv
package NetFox; >|rU*+I`
V'8Rz#Gc5
}G ^nK m
public class TestMethod { *cy!PF&
G0lg5iA<fC
r E&}B5PN=
public TestMethod() 2o<aEn&7|e
{ ///xx/weblogic60b2_win.exe W}P9I&3
try{ DR(/|?k+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Oq[YbQ'GE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); giHWC%/
SiteFileFetch fileFetch = new SiteFileFetch(bean); zrL+:/t
fileFetch.start(); q^eLbivVE
} nC5]IYL|
catch(Exception e){e.printStackTrace ();} VLcwBdo
,DD}o
ho%G
} h'"~t#r
hH~GH'dnaE
2v`Q;%7O
public static void main(String[] args) s-Qq#T
{ kLe{3>}j
new TestMethod(); 6^sH3=#
} xs^wRE_
} <"@5. f1"Y
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