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)); ox&PFI0Gn
} 937 z*mh
for(int i=0;i<nEndPos.length-1;i++) Ht,dMt>:
{ hh1 ?/
nEndPos = nStartPos[i+1]; |l#<vw wE
} \$B%TY
nEndPos[nEndPos.length-1] = nFileLength; yd>b2 M
} ih[!v"bv
} OBm#E}
4]P5k6nV
cOz/zD f5
//启动子线程 !VoAN5#;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R2`-*PZ_
for(int i=0;i<nStartPos.length;i++) (]}52%~
{ ]aDU*tk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?\.DG`Zxc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D00v"yp%%
nStartPos,nEndPos,i); zcrM3`Zh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #JD:i%
fileSplitterFetch.start(); oj'a%mx
} a:V2(nY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2Vwv#NAV k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1!P\x=Nn_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IBn+42V
nEndPos = " + nFileLength); Hdxon@,+cd
// fileSplitterFetch[nPos.length-1].start(); jY|fP!?[
<{Pr(U*7}
7J6D wh{
//等待子线程结束 m(0c|-
//int count = 0; dR|*VT\
//是否结束while循环 - fx?@
boolean breakWhile = false; Gdu5 &]H#6
)a=58r07
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while(!bStop) tSf$`4
{ :g~X"C1s
write_nPos(); TaqqEL
Utility.sleep(500); DKnlbl1^?
breakWhile = true; rQLl[a
[~v1
CUI\:a-
for(int i=0;i<nStartPos.length;i++) K4w#}gzok
{ +f"q^RIU
if(!fileSplitterFetch.bDownOver) 6M^NZ0~J
{ _B6W:k|-7l
breakWhile = false; iU1yJ=
break; /9o gg
} hziPHuK9,
} vvwQ/iJO4Q
if(breakWhile) \nbGdka
break; "+sl(A3`U
,CED%
p2I9t|
//count++; P~^VLnw
//if(count>4) Iss)7I
// siteStop(); WV?3DzeR
} 0vjlSHS;`.
q?0&&"T}
=&,<Co1hF
System.err.println("文件下载结束！"); +aoenUm5
} ?"Ec#,~
catch(Exception e){e.printStackTrace ();} 5fjL
} 98ot{+/LK
-`s_md0BM
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//获得文件长度 J`d_=C?J
public long getFileSize() ah2L8jN"
{ BTAt9Z8qK
int nFileLength = -1; 3vC"Q!J&
try{ ( C~ u.
URL url = new URL(siteInfoBean.getSSiteURL()); kes GwMr"e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {4^NZTjd@
httpConnection.setRequestProperty("User-Agent","NetFox"); , #nYHD
j#rj_uP
m3']/}xHO
int responseCode=httpConnection.getResponseCode(); x;@wtd*QB
if(responseCode>=400) !l|fzS8g
{ *u ^mf~
processErrorCode(responseCode); 'i;/?'!W6
return -2; //-2 represent access is error De^Uc
} #O,;3S
AA &>6JB{
I3^}$#>
String sHeader; \C&V)/
;^f ;<
HE{JiAf
for(int i=1;;i++) <.knM
{ B }t529Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nAT,y9&
//Utility.log(in.readLine()); X"EZpJ'W
sHeader=httpConnection.getHeaderFieldKey(i); L )53o!
if(sHeader!=null) C;\R 62'
{ ^hRx{A
if(sHeader.equals("Content-Length")) M;j)F
{ 7wz9x8\t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); khQ@DwO*\=
break; (8td0zq
} \<u
} p?V@P6h
else `_+%
break; ^|UD&6 dx
} 8s9ZY4_
} 9$s~ `z)
catch(IOException e){e.printStackTrace ();} sL4j@Lt
catch(Exception e){e.printStackTrace ();} Y{I,ipU.
M{4U%lk
wO&+Bb\=
Utility.log(nFileLength); m"f3hd4D_q
:-tMH02c
`DS7J\c$
return nFileLength; 1"S~#
} oxNQNJ!X
RMs+pN<5
+5"Pm]oRbx
//保存下载信息（文件指针位置） :6jh*,OHZl
private void write_nPos() 5kLz8n^z@@
{ a\B'Qe+
try{ E RjMe'q4
output = new DataOutputStream(new FileOutputStream(tmpFile)); k"F\4M
output.writeInt(nStartPos.length); p+#]Jr
for(int i=0;i<nStartPos.length;i++) S0w:R:q}L
{ o@[oI\Vr!
// output.writeLong(nPos); cD ?'lB-
output.writeLong(fileSplitterFetch.nStartPos); fk2p}
output.writeLong(fileSplitterFetch.nEndPos); ows3%
} +}x\|O
output.close(); O39f
} N oRPvFv
catch(IOException e){e.printStackTrace ();} fL~@v-l#~
catch(Exception e){e.printStackTrace ();} Sb.%B^O
} 0b}.!k9
*h M5pw
PVaqKCj:6W
//读取保存的下载信息（文件指针位置） 5S 4Bz
private void read_nPos() 88On{Kk.v
{ 9xOTR#B:_V
try{ }v6@yU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Zg$RiQ^-{J
int nCount = input.readInt(); \p#_D|s/Ep
nStartPos = new long[nCount]; ~oz??SX
nEndPos = new long[nCount]; 3c+ps;nh
for(int i=0;i<nStartPos.length;i++) Ejj+%)n.
{ QxT\_Nej*n
nStartPos = input.readLong(); oVQbc\P3
nEndPos = input.readLong(); >';UF;\5]Q
} 9`tSg!YOh
input.close(); +1nzyD_E
} W H%EC$
catch(IOException e){e.printStackTrace ();} GL,( N|
catch(Exception e){e.printStackTrace ();} e=`=7H4P
} IL{tm0$r
!3)WW)"!r
t!\B6!Fo
private void processErrorCode(int nErrorCode) &3 *#h
{ r"!xI
System.err.println("Error Code : " + nErrorCode); ;r}yeISf
} sBa&]9>m
@?*; -]#)
^$s&bH'8
//停止文件下载 e2kW,JV/<$
public void siteStop() }H:wgy`
{ LZDJ\"a-
bStop = true; Y)2#\ F
for(int i=0;i<nStartPos.length;i++) (_=R<:
fileSplitterFetch.splitterStop(); r7FpR!
"R]wPF5u
1D1qOg"LE
} fZb}-
} Gn^m541
//负责部分文件的抓取 X#tCIyK,nV
**FileSplitterFetch.java JHa\"h
*/ &qP0-x)
package NetFox; bnZ H
[l}H%S
x/0loW?q^
import java.io.*; t==\D?Rt
import java.net.*; S0`u!l89(
VIg6'
|nBs(>b
public class FileSplitterFetch extends Thread { U|Uc|6
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54#P
String sURL; //File URL FuC\qF
long nStartPos; //File Snippet Start Position xdh%mG:?
long nEndPos; //File Snippet End Position \027>~u {
int nThreadID; //Thread's ID Py#TXzEcC
boolean bDownOver = false; //Downing is over 9Dp0Pi?29
boolean bStop = false; //Stop identical SqZ .}s
FileAccessI fileAccessI = null; //File Access interface &gcZ4gpH
4 %V9
gv){&=9/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _'l"Dk
{ Ol;DJV
this.sURL = sURL; xnHB <xrE}
this.nStartPos = nStart; 5\}E4y
this.nEndPos = nEnd; g3 Oro}wt6
nThreadID = id; ={;7WB$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L{oG'aK4
} &ET$ca`j#
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public void run() /=g/{&3[a>
{ -Jt36|O
while(nStartPos < nEndPos && !bStop) Z!3R
{ 8nwps(3
<[K3Prf C
@`ii3&W4
try{ Dus!Ki~8(t
URL url = new URL(sURL); 0lV;bVa%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l,Fn_zO
httpConnection.setRequestProperty("User-Agent","NetFox"); fL*+[v4
String sProperty = "bytes="+nStartPos+"-"; I%NeCd
httpConnection.setRequestProperty("RANGE",sProperty); SgssNv
Utility.log(sProperty); a#lytp
rBOH9L
gq@8Z AWn
InputStream input = httpConnection.getInputStream(); 2@IL n+#
//logResponseHead(httpConnection); %cBOi_}}~
iNc!zA4
N6`U)=2o>h
byte[] b = new byte[1024]; hM[3l1o{|
int nRead; *qu5o5Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bGkLa/?S
{ #M4LG; B
nStartPos += fileAccessI.write(b,0,nRead); #lc6-K#
//if(nThreadID == 1) =zu;npM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `"hWbmQ
} Kv)}
Fv$A%6;W
'$rCV,3q
Utility.log("Thread " + nThreadID + " is over!"); {+GR/l\!#
bDownOver = true; EM`'=<)V
//nPos = fileAccessI.write (b,0,nRead); K-@\";whF
} "$D'gSoYe
catch(Exception e){e.printStackTrace ();} 'Lw8l `7
} mn\A)RQ
} Gpi_p
,Xr`tQ<@
bI`JG:^b
//打印回应的头信息 bZr,jLEf
public void logResponseHead(HttpURLConnection con) ?1zGs2Qs
{ ^;F5ymb3U
for(int i=1;;i++) +25=u|#4r
{ G"tlJ7$myQ
String header=con.getHeaderFieldKey(i); V.6pfL
if(header!=null) 8I Ip,#%v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v??$z#1F3
Utility.log(header+" : "+con.getHeaderField(header)); hn\d{HP
else h-RhmQA=Iz
break; Sk)lT^by
} R$66F>Jz^
} xR8.1T?8
<EcxNj1
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public void splitterStop() Ji:<eRx)
{ 9_?e, Q
bStop = true; Go^TTL
} h&n1}W+
s~bi#U;dF
t\a|Gp W
} p&5>j\uJ1&
y/kB`Z(Yj
0igB pHS
/* qVI0?B x
**FileAccess.java =9W\;xE S
*//文件访问(定位，写) rV4K@)~
package NetFox; sH_,P
import java.io.*; 3~V.
2Q\\l @b\
$zU%?[J
public class FileAccessI implements Serializable{ e$2P/6k>
O1)\!=& .
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vU5}E\Ny
RandomAccessFile oSavedFile; (CgvI*O
long nPos; bar=^V)
8ZqLGa]
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public FileAccessI() throws IOException F3]VSI6^E,
{ Lq1?Y
this("",0); K#AexA
} &:IcwD&
E/*&'Osq
cIG7Q"4
public FileAccessI(String sName,long nPos) throws IOException "a}fwg9Y
{ z6rT<~xZtu
oSavedFile = new RandomAccessFile(sName,"rw"); i;s;:{cn
this.nPos = nPos; Pr(@&:v:
oSavedFile.seek(nPos); { PJ>gX$
} Gk/cP`
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{:#nrD"
public synchronized int write(byte[] b,int nStart,int nLen) >iRkhA=Vg
{ 3-,W? "aC
int n = -1; s@5~HyeI
try{ iP;"-Mj
oSavedFile.write(b,nStart,nLen); )p1~Jx(\
n = nLen; y Vm>Pj6
} X{Hh^H
catch(IOException e) XZM@Rys
{ ;gSRpTS:
e.printStackTrace (); y1T(R#
} g>;@(:e^/
w=n(2M56C
J 7G-qF\
return n; tq3Rc}
} %>_6&A{K,d
%=Z/Frd
j*Pq<[~
} MpGG}J[y
j7Ts&;`[*
rUmP_
/* FMI1[|:;
**SiteInfoBean.java lw[c+F7
*/ FKu8R%9xn%
package NetFox; ed}#S~4q
dFDf/tH
i}P{{kMJ
public class SiteInfoBean { ;RX u}pd
v=0G&x=/
3Jlap=]68S
private String sSiteURL; //Site's URL 4oueLT(zc
private String sFilePath; //Saved File's Path O!{YwE8x9
private String sFileName; //Saved File's Name V+y"L>K
private int nSplitter; //Count of Splited Downloading File Up'#OkTx
{7@*cBqN
s</qT6@
public SiteInfoBean() z F.@rXl
{//nSplitter的缺省值为5 {GLGDEb
//default value of nSplitter is 5 jBOl:l,+
this("","","",5); h=:/9O{H
} b=_k)h+l
eh `%E0b}
%K-8DL8|(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '&B4Ccn<V
{ \yFUQq:
sSiteURL= sURL; wW1\{<hgr
sFilePath = sPath; 4C%pKV
sFileName = sName; <Nqbp
this.nSplitter = nSpiltter; {.jW"0U
)y;7\-K0
_/noWwVu
} O0xqA\
2M'dTXz
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public String getSSiteURL() /\h*v!:
{ ktx| c19
return sSiteURL; D_0Vu/v
} /OzoeIt
=3w;<1 ?'
9 %4:eTcp
public void setSSiteURL(String value) ;tZQ9#S
{ ^PezV5(
sSiteURL = value; y^`JWs,
} Y.]$T8
X_hDU~5{wC
!Kg']4
public String getSFilePath() ?\,^>4x?
{ usD@4!PoA
return sFilePath; -Z$u[L [c
} aE9Y |6
=!^ gQ0~4
QO(F%&v++
public void setSFilePath(String value) !p/?IW+
{ ?`rAO#1
sFilePath = value; VDbbA\
} v#/Gxk9eX
@|c])
QR'#]k;>%
public String getSFileName() w"s@q$}]8M
{ FZj>N(
return sFileName; k-=LD
} aW&)3C2-x
II}M|qHaK
5HV+7zU5
public void setSFileName(String value) ,_RNZ sa;&
{ %csrNf
sFileName = value; Dz6xx?
} 3yKmuu!
rFQWgWD
n@p@@
public int getNSplitter() ={zTQ+7S`
{ 3EICdC
return nSplitter; ^.!jD+=I
} hyf ;f7`o
]>VG}e~b
>- \bLr
public void setNSplitter(int nCount) ")STB8kQ
{ nwUz}em?O
nSplitter = nCount; q_h (D/g
} V&s|IoTR
} za@/4z
uwSSrT
0>N6.itOz
/* J4"Fj, FS
**Utility.java fyb;*hgu
*/ MkPQ@so
package NetFox; KddCR&
kY~4AH
j/*1zu8Y
public class Utility { *b. >
nJ2x;';lA
g=56|G7n
public Utility() i#`q<+/q
{ \H@1VgmR;
c_D(%Vf5
_b~{/[s
} aLGq<6Ja
Lr$Mk#'B
//线程睡眠 {4G/HW28
public static void sleep(int nSecond) K%? g6j
{ Ptv'.<-
try{ T+F]hv'
Thread.sleep(nSecond); 0\= du
} Tn#Co$<
catch(Exception e) p2i?)+z
{ {}$7Bp
e.printStackTrace (); EyE#x_A
} Z_\p8@3aH
} MVsFi]-
akzGJ3g
//日志 4\Y5RfLB_
public static void log(String sMsg) 0+*NHiH
{ pi?MAE*f
System.err.println(sMsg); GT&}Burl/n
} -V|"T+U
%'=*utOxy
zXn-E
public static void log(int sMsg) PC#^L$cg}
{ #_wq#rF
System.err.println(sMsg); $s/E}X
} >5t%_/yeB
} xV)[C )6
AAevN3a#nI
vt|R)[,
/* g4[VgmhJ
**TestMethod.java !wfW0?eu
*/ ##7y|AwK
package NetFox; GkIY2PD
N7+L@CC6T
6QX m]<
public class TestMethod { `OBzOM
YNEwX$)M,B
JNfL jfE)<
public TestMethod() ) CP
{ ///xx/weblogic60b2_win.exe cQU;PH]
try{ \!-BR0+y;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "+F'WCJ-(*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EO&Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); "]+g5G
fileFetch.start(); JL1ajlm~
} WEimJrAn
catch(Exception e){e.printStackTrace ();} o8bdL<
^}_Ka//k
WTJ 0Q0U
} 1`&`y%c?B
hxO}'`:
bO=|utpk
public static void main(String[] args) h+FM?ct6}
{ &0F' Ca
new TestMethod(); `@/)S^jBau
} m+TAaK
} 1UP=(8j/
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