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)); &_" 3~:N8k
} \5s!lv*&
for(int i=0;i<nEndPos.length-1;i++) #%k5s?cP@
{ t=XiSj\n
nEndPos = nStartPos[i+1]; l3-KswU
} Fj1/B0acS
nEndPos[nEndPos.length-1] = nFileLength; '(2G qX!
} |+!Jr_ By
} X?>S24I"9
tjDVU7um
wjS3ItB
//启动子线程 l-t:7`=|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YvBUx#\
for(int i=0;i<nStartPos.length;i++) b\=0[kBQw
{ ;a{ Dr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C9gF2ii|?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), deHBY4@
nStartPos,nEndPos,i); +]uy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !G\1$"T$
fileSplitterFetch.start(); 8"oS1W
} {:6VJ0s\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vy}:Q[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w/YKWv{_S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4yRT!k}o
nEndPos = " + nFileLength); 5U1@wfKE3>
// fileSplitterFetch[nPos.length-1].start(); bXJ,L$q
C!qW:H
eDaVoc3
//等待子线程结束 $|(roC(
//int count = 0; @|-ydm0
//是否结束while循环 IFG`
boolean breakWhile = false; *ZN"+wf\
E_ mgYW*5
CXUNdB
while(!bStop) wfo}TGhC
{ lJ7k4ua\
write_nPos(); m?[F)<~a
Utility.sleep(500); t$\]6RU
breakWhile = true; O,^,G<`
>IoOCQQ*
!m_'<=)B4~
for(int i=0;i<nStartPos.length;i++) $9W9*WQL
{ j{p0yuZ)<
if(!fileSplitterFetch.bDownOver) ).v;~yE
{ OEB_LI'
breakWhile = false; D#(A?oN
break; X+&@$v1
} diTzolY7
} sGdt)
if(breakWhile) .':SD{
break; _9L2JN$R6
?:U6MjlQ"{
oWXvkDN
//count++; &2QN^)q
//if(count>4) rycscE4,
// siteStop(); 2a? d:21 B
} \BJnJk!%
w'L;`k;Q
UKX'A)$
System.err.println("文件下载结束！"); F+hsIsQ
} 3*8#cSQ/6o
catch(Exception e){e.printStackTrace ();} <~: g
} T*YdGIFO
l8^^ O
Q8\Ks|u]
//获得文件长度 |nm,5gPNC
public long getFileSize() Yq1 ~"he8
{ jRgv 8n
int nFileLength = -1; M.|hnGXN
try{ P_b00",S
URL url = new URL(siteInfoBean.getSSiteURL()); Bb-x1{t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,{E'k+
httpConnection.setRequestProperty("User-Agent","NetFox"); Xc Pn
k)S7SbQ
+d#ZSNu/
int responseCode=httpConnection.getResponseCode(); ss,6;wfX
if(responseCode>=400) r/{0YFa
{ t$Qav>D
processErrorCode(responseCode); i ;X'1TN(y
return -2; //-2 represent access is error -sc@SoS
} hKX-]+6"
D}3E1`)W
Nk^#Sa?
String sHeader; u!g<y
VK$+Nm)
zH|!O!3"4
for(int i=1;;i++) JY>]u*=
{ CrqWlO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q>sq:R+'
//Utility.log(in.readLine()); {a(YV\^y|H
sHeader=httpConnection.getHeaderFieldKey(i); D, 3x:nK
if(sHeader!=null) Y9PG
{ (_-zm)F7
if(sHeader.equals("Content-Length")) z` gR*+
{ M?F({#]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T_\GvSOI
break; T}4RlIZF
} nnr(\r~
} Qz/=+A/4
else )9@Ftzg|
break; '<XG@L
} n*_FC
} ri\r%x
catch(IOException e){e.printStackTrace ();} {},GxrQm
catch(Exception e){e.printStackTrace ();} E-!`6
!FO||z(vb
sq :ff
Utility.log(nFileLength); pLk?<y
tSQ>P -O
?rr%uXQjH
return nFileLength; E@[`y:P
} :r#FI".qx
a2p<HW;)m
5ue{&z @T
//保存下载信息（文件指针位置） 81aY*\
private void write_nPos() ^Z}INUv]7
{ iL5+Uf)E3
try{ tK]r>?Y\
output = new DataOutputStream(new FileOutputStream(tmpFile)); .;$/nz6vk
output.writeInt(nStartPos.length); %2qvK}
for(int i=0;i<nStartPos.length;i++) )8LCmvQ
{ Zkxt>%20~
// output.writeLong(nPos); &WsDYov?
output.writeLong(fileSplitterFetch.nStartPos); jQ7RH/?_
output.writeLong(fileSplitterFetch.nEndPos); Y{2\==~
} .s,hl(w,
output.close(); QEtZ]p1H@
} r%TgZ5~u
catch(IOException e){e.printStackTrace ();} <\yM{ V\
catch(Exception e){e.printStackTrace ();} t|%iW%m4
} e `_ [+y
r$.ek\D5
i<&2Ffvq
//读取保存的下载信息（文件指针位置） v( (fRX.`
private void read_nPos() *4+;Ey
{ BU])@~$
try{ qFvtqv2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m: w/[|_
int nCount = input.readInt(); :Fm+X[n
nStartPos = new long[nCount]; Pm;"Y!S<
nEndPos = new long[nCount]; x{&Z|D_CM
for(int i=0;i<nStartPos.length;i++) t ZFG`'/
{ wRUpQ~=B2
nStartPos = input.readLong(); j;<;?IW
nEndPos = input.readLong(); {)jQbAr(G
} w9z((\5
input.close(); PVV\@
} i' N
catch(IOException e){e.printStackTrace ();} z!t&zkAK
catch(Exception e){e.printStackTrace ();} ##yi^;3Y
} #nn2odR
VN;Sz,1Z
q=|>r n_
private void processErrorCode(int nErrorCode) KVqQOh'_T
{ %'EOFv]
System.err.println("Error Code : " + nErrorCode); w,JB`jS)/
} KWhw@y-5j@
U7 Z_
+mV4Ty
//停止文件下载 ks'25tv}F
public void siteStop() SOeL@!_
{ v#D9yttO{
bStop = true; SAXjB;VH6
for(int i=0;i<nStartPos.length;i++) 6P+8{?V&
fileSplitterFetch.splitterStop(); ~@L$}Eu
j1<@*W&b
GD.mB[f*
} nvpdu)q<
} 0nA17^W
//负责部分文件的抓取 zD2Bhta y
**FileSplitterFetch.java ~vaV=})
*/ %n!s{5:F
package NetFox; 8M:;9a8fh
R-hqaEB
Z/56JYt!~
import java.io.*; g4%x7#vz0
import java.net.*; &87D.Yy^
1<fEz
J%D'Xlb
public class FileSplitterFetch extends Thread { d) G7U$z~
4$ejJaE
E%jOJA
String sURL; //File URL tse(iX/D
long nStartPos; //File Snippet Start Position aI+:rk^
long nEndPos; //File Snippet End Position Fi(_A
int nThreadID; //Thread's ID Y@RPQPmIQ
boolean bDownOver = false; //Downing is over +Bc/@.Q'
boolean bStop = false; //Stop identical =s1"<hH}O)
FileAccessI fileAccessI = null; //File Access interface Qh)@-r3
Q_LPLmM
r~TiJ?8I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hGD7/qTN
{ ':F{st>&H
this.sURL = sURL; *1}9`$
this.nStartPos = nStart; -\AB!#fh
this.nEndPos = nEnd; S1%{/w
nThreadID = id; (a]'}c$X9`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [*8wv^
} luLm:NWUM
8R8J./i.K
5GT,:0
public void run() ZK3?"|vhC
{ A$fd6+{
while(nStartPos < nEndPos && !bStop) HIi"zo=V
{ &=t$ AIu
1OE^pxfi>
&RpQ2*4n
try{ %^gT.DsX-
URL url = new URL(sURL); %+FM$xyJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =@V4V} ?
httpConnection.setRequestProperty("User-Agent","NetFox"); ~SP.&>Q>
String sProperty = "bytes="+nStartPos+"-"; |5$9l#e
httpConnection.setRequestProperty("RANGE",sProperty); #y}@FG
Utility.log(sProperty); #C4
0>VgO{X
k`2 K?9\
InputStream input = httpConnection.getInputStream(); xWn.vSos
//logResponseHead(httpConnection); D-A#{e _
Hfm4
`H^Nc\P#
byte[] b = new byte[1024]; GAtK1%nPD
int nRead; :#c?`>uV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W{ @lt}
{ S1E2E3
nStartPos += fileAccessI.write(b,0,nRead); 3 +BPqhzf
//if(nThreadID == 1) qmOGsj`#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =<O{
} 6i%LM`8GEk
a%Cq?HZ7
/ D#vs9S
Utility.log("Thread " + nThreadID + " is over!"); 241YJ
bDownOver = true; SU2(XP]5
//nPos = fileAccessI.write (b,0,nRead); (al7/EhY
} fZxZ):7i
catch(Exception e){e.printStackTrace ();} Nki18ud#
} iN+p>3w^l
} -!(3fO:
\9@*Jgpd6*
KW^s~j
//打印回应的头信息 VlXIM,
public void logResponseHead(HttpURLConnection con) Z]uN9c
{ $//18+T
for(int i=1;;i++) f+%J=Am
{ $vlgiJ&f
String header=con.getHeaderFieldKey(i); uSM4:!8
if(header!=null) SECL(@0(^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BAdHGwomh
Utility.log(header+" : "+con.getHeaderField(header)); z`>a,X
else r"Pj,}$A
break; %49@
} qJ#?=ITE
} c<DsCzX
+lO Y IQ
\qV5mD]"M
public void splitterStop() >xJt&jW-
{ {B?%r[nW
bStop = true; 06 K8|K
} ` n@[=l~
' OdZ[AN
mL18FR N
} 7<|1 xOT
A$Es(<'9g
V4/P
/* v?fB:[dG
**FileAccess.java Y@M=6G
*//文件访问(定位，写) hLYSYMUb
package NetFox; Uu>YE0/)
import java.io.*; f==o
[$8*(d"F'
ElqHZ$a?
public class FileAccessI implements Serializable{ 3f eI
OtY.s\m y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }1z= C<
RandomAccessFile oSavedFile; <)?H98S
long nPos; 7{8!IcR #
q|=tt(}G
%zb7M%dC6`
public FileAccessI() throws IOException &=X1kQG
{ QbxjfW"/+
this("",0); (@uQ>dR:
} g0cCw2S
Qn[4&nUD
P,CJy|[L
public FileAccessI(String sName,long nPos) throws IOException p Ic;9
{ *G'zES0x
oSavedFile = new RandomAccessFile(sName,"rw"); @T?:[nPf&F
this.nPos = nPos; R4E0avt
oSavedFile.seek(nPos); .<rL2`C[c
} kOFEH!9&
_+z@Qn?#6h
}Jh!B|
public synchronized int write(byte[] b,int nStart,int nLen) 7s<v06Wo
{ f!xIMIl)+
int n = -1; 1PjSa4
try{ zu*0uL
oSavedFile.write(b,nStart,nLen); AG/nX?u7)t
n = nLen; Fl(+c0|kT
} W\N-~9UA
catch(IOException e) b0riiF
{ Xb)XV$0
e.printStackTrace (); $M$oNOT}Y
} T7Lk4cU
9n|H%AC
xqmJPbA
return n; %}+j4n
} Y\dK-M{$
$hg W>e
"aB]?4
} yr[iAi"
kx]f`b
a!Z,~ V8
/* |1-0x%@[;
**SiteInfoBean.java kS/Zb3
*/ ULjW589zb
package NetFox; B%^B_s
<4rF3 aB-
;G;vpl
public class SiteInfoBean { 3L=vsvO4
:pDwgd
<IK8Ucp
private String sSiteURL; //Site's URL DK*2d_
private String sFilePath; //Saved File's Path 9i,QCA
private String sFileName; //Saved File's Name !@ai=p
private int nSplitter; //Count of Splited Downloading File 4LUFG
|+cyb<(V J
<ynmA
public SiteInfoBean() \hv*`ukF
{//nSplitter的缺省值为5 #u|;YC
//default value of nSplitter is 5 i. `S0
this("","","",5); N@?Fpmu/k
} `"A\8)6-
]Ny. gu
x4.-7%VV%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nDui9C
{ /_o1b_1U
sSiteURL= sURL; z=n"cE[KtB
sFilePath = sPath; )-2OraUm<
sFileName = sName; xI}]q%V
this.nSplitter = nSpiltter; n&FN?"I/]
&P[eA u
AM'-(x|
} -Ww'wH'2
:Oa|&.0l?
'u_'y
public String getSSiteURL() fCO!M1t
{ Ks8S^77
return sSiteURL; b==<7[8
} 7!Ym~M=
o LuGW5wzj
*1Nz VV
public void setSSiteURL(String value) .OXvv _?<
{ HWVWl~FA
sSiteURL = value; k2k/v[60
} *oZBv4Vh
_d %H;<_
lwQI 9U[O2
public String getSFilePath() 5a5I+* c
{ 2+sNt6B2
return sFilePath; &0Wv+2l@
} &"K74
H5^'J`0\
J3S@1"
public void setSFilePath(String value) 2@uo2]o)
{ |1T2<ZT
sFilePath = value; Mf/zSQk+
} 0&2TeqsLh)
MFiX8zwhx+
|v[{k>7f
public String getSFileName() %89f<F\V
{ ;}=v|Dr&I.
return sFileName; A4Q8^^byY
} **fJAANc
cl^wLC'o
%]r@vjeyd
public void setSFileName(String value) xo7H^!_
{ d_1w 9FA
sFileName = value; EoIP#Cnd1
} "Z&{
{-7];e
w[~$.FM/
public int getNSplitter() 6_^u}me
{ m`I6gnLj
return nSplitter; HGh`O\f8
} |XLx6E2F
-81usu&NH
O292JA
public void setNSplitter(int nCount) V78QV3
{ b H?dyS6Bx
nSplitter = nCount; #RbPNVs
} '7u#uL,pa1
} [-{L@
F?T3fINR
4WzB=C(f
/* )+u|qT3%
**Utility.java CmY'[rI
*/ RUlM""@b
package NetFox; ncu &<j}U
=5[}&W
l{\~I
public class Utility { w2@ `0
~{=+dQ
FxTOc@<
public Utility() CsQ}eW8uEf
{ UF|v=|*{#
Uj(,6K8W
R`:Y&)c_$
} ]uWx<aDB
6wqq"6w
//线程睡眠 b U-Cd
public static void sleep(int nSecond) \3O#H
{ =V/$&96Q
try{ <&t^&6k
Thread.sleep(nSecond); O<)"kj 7
} Z>wg o@z%
catch(Exception e) s@jzu
{ Fwm{oypg%
e.printStackTrace (); [8^jwnAYS
} NMJ230?
} j_o6+Rk
0^?3hK
//日志 ?Q]&d!UCs
public static void log(String sMsg) zq8z#FN
{ Q*^zphT
System.err.println(sMsg); A@?2qX^4
} 0>)('Kv
;B:'8$j$
kC!7<%(
public static void log(int sMsg) B+`m
{ KNic$:i
System.err.println(sMsg); ]$EKowi
} 15)=>=1mR.
} c_yf=
:05>~bn>pC
k10dkBoEX
/* pV=X
**TestMethod.java :eo2t>zF-<
*/ Om\?<aul
package NetFox; 0N;Pb(%7UU
"e&S*8QhM
k =ru) _$2
public class TestMethod { z%}^9
(fUXJ$
cZe,l1$
public TestMethod() S"!nM]2L
{ ///xx/weblogic60b2_win.exe #W @6@Mv
try{ erdWGUfQOe
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r\F`xtR(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2w$o;zz1
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^}ngbDn
fileFetch.start(); b*no.eB
} gLaFIeF<+
catch(Exception e){e.printStackTrace ();} l-Xxur5M'
`jSxq66L p
`9(TqcE
} +w?RW^:Q=
9F(<n
2ZNTj u7h
public static void main(String[] args) <*i '
{ 1ZJP.T`
new TestMethod(); ^.&2-#i
} Q$iYhR
} |O%`-2p]p
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