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)); >-T`0wI
} *, Ld/O;s
for(int i=0;i<nEndPos.length-1;i++) (dJI_A
{ 'f8(#n=6qP
nEndPos = nStartPos[i+1]; ocwG7J\W
} N5|Rmfo1
nEndPos[nEndPos.length-1] = nFileLength; #)+- lPe
} 1`f_P$&Z_J
} @ \.;b9
^s7,_!.Pq
!2Dy_U=
//启动子线程 |ifHSc.j<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sfp,Lq`
for(int i=0;i<nStartPos.length;i++) 9z m|Lbj
{ [{[N(g&d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k0?ZYeHC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ue5O9;y]u
nStartPos,nEndPos,i); UIJx*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x9>\(-uU
fileSplitterFetch.start(); '6Qy/R
} qg z*'_S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NCeaL-y7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {!ZyCi19
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XCB?ll*^
nEndPos = " + nFileLength); r'/;O
// fileSplitterFetch[nPos.length-1].start(); OL59e%X
ofc.zwH
,reJ(s
//等待子线程结束 =<f-ob8,
//int count = 0; jdut4 nFc
//是否结束while循环 `Y?t@dd
boolean breakWhile = false; hVoNw6fE
$KV&\Q3\0
<x%M3BTx
while(!bStop) Dkw%`(Oh/,
{ O[~x_xeW
write_nPos(); S{F-ttS"
Utility.sleep(500); 4Tzd; P6_
breakWhile = true; uE_c4Hp
xc 1A$EY
+,'T=Ic{
for(int i=0;i<nStartPos.length;i++) zbw7U'jk
{ `cP <}^]
if(!fileSplitterFetch.bDownOver) \L!uHAE2a
{ `&7RMa4=
breakWhile = false; A Ayv
break; <T,A&`/
} `ue[q!Qq
} :bM+&EP
if(breakWhile) `linG1mF
break; 8"'x)y
'3tw<k!1{.
H!r &aP
//count++; *}b]rjsj
//if(count>4) hP?fMW$V
// siteStop(); ^~ =9
} A//?6OJx?
l?N`{,1^
>.9eBz@
System.err.println("文件下载结束！"); _v5t<_^N
} sOFa!bdPW
catch(Exception e){e.printStackTrace ();} JXQPT
} }amU[U,
;|ub!z9GG
>G)qns9
//获得文件长度 dT@UK^\
public long getFileSize() 4z4v\IpB
{ o.:p_(|hI
int nFileLength = -1; ~GB=Nz
try{ 85U.wpG
URL url = new URL(siteInfoBean.getSSiteURL()); _"f :`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N$aZ== $5
httpConnection.setRequestProperty("User-Agent","NetFox"); uF(k[[qaiN
/9ZcM]X B
B:oF;~d/,
int responseCode=httpConnection.getResponseCode(); I@7/jUO
if(responseCode>=400) r((Tavn
{ :Z`4j
processErrorCode(responseCode); c,5n,i
return -2; //-2 represent access is error $N+6h#
} "X1vZwK8N
*$,+`+
i s"vekC
String sHeader; y).P=z
V2znU
Rq)BssdF
for(int i=1;;i++) R"xp%:li
{ H3FW52pjX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z[#IfbYt
//Utility.log(in.readLine()); Ueyw;Y
sHeader=httpConnection.getHeaderFieldKey(i); n[k1np$7?6
if(sHeader!=null) ?T*";_o,B
{ OD9 yxN>P
if(sHeader.equals("Content-Length")) *K!++k!Ixa
{ I@Z)<5Zf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x!{
break; 0Oxz3r%}r
} CmC0k-%w
} >q( 5ir
else D!FaEN
break; ," R>}kPli
} KsdG(.I+ek
} a8uYs DS
catch(IOException e){e.printStackTrace ();} 1p\Ak
catch(Exception e){e.printStackTrace ();} qc8Ta"
7[o {9Yp&
"n?<2 wso
Utility.log(nFileLength); 6 DP[g8
`.BR=['O
UmP'L!
return nFileLength; 2R@%Y/
} 9U<Hf32
&TT":FPR
V/y=6wUiSl
//保存下载信息（文件指针位置） 9{eBgdC
private void write_nPos() cH"@d^"+q|
{ gbGTG(:1S
try{ "EPD2,%S
output = new DataOutputStream(new FileOutputStream(tmpFile)); HhSjR%6HY;
output.writeInt(nStartPos.length); }p'8w\C$
for(int i=0;i<nStartPos.length;i++) =7jEz+w#
{ l1-HO
// output.writeLong(nPos); qi=3L
output.writeLong(fileSplitterFetch.nStartPos); :c4kBl%gJ
output.writeLong(fileSplitterFetch.nEndPos); pCt}66k}
} #)74X%4(
output.close(); !IAKVQ
} DX@}!6|T
catch(IOException e){e.printStackTrace ();} FBYODw
catch(Exception e){e.printStackTrace ();} B=zMYi
} Q=+8/b
nR'#s%Kj
*SZ>upg
//读取保存的下载信息（文件指针位置） -V=arm\#z
private void read_nPos() M\UWWb&%\
{ "{F;M{h$},
try{ 'Z[d7P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9*pG?3*I
int nCount = input.readInt(); 3%IWGmye4
nStartPos = new long[nCount]; z\}!RBOq
nEndPos = new long[nCount]; { /<4'B
for(int i=0;i<nStartPos.length;i++) _T~H[&Hl
{ =lrN'$z?%
nStartPos = input.readLong(); |~NeB"l{
nEndPos = input.readLong(); X<xqT
} 878tI3-
input.close(); h)o]TV
} u2lmwE
catch(IOException e){e.printStackTrace ();} *Q/E~4AW|t
catch(Exception e){e.printStackTrace ();} .BL:h&h|y
} raQYn?[
Nmf#`+7gCI
<nA3Sd"QfV
private void processErrorCode(int nErrorCode) AQ}l%
{ 3wNN<R
System.err.println("Error Code : " + nErrorCode); 4(m3c<'P
} *|'}v[{v^9
^<9)"9)m_
"jGe^+9uT
//停止文件下载 ? ).(fP
public void siteStop() MZ^Ch
{ E& ]_U$
bStop = true; >sV Bj(f
for(int i=0;i<nStartPos.length;i++) r}@< K
fileSplitterFetch.splitterStop(); ~7BX@?
Qa?QbHc
vs*I7<
} ;U7t
} M9g1d7%
//负责部分文件的抓取 AIfk"2
**FileSplitterFetch.java w:R]!e_6\9
*/ V'yxqI?
package NetFox; oZvG3_H4.
m/N(%oMWB=
,CW%JIM
import java.io.*; L&HzN{K
import java.net.*; m?vAyi
~y%7w5%Un
Ja=N@&Z#
public class FileSplitterFetch extends Thread { 3mA/Nu_
Ib(,P3
-9Xw]I#QR
String sURL; //File URL p,^>*/O>
long nStartPos; //File Snippet Start Position dh,7iQ s
long nEndPos; //File Snippet End Position |ZuDX87
int nThreadID; //Thread's ID | VRq$^g
boolean bDownOver = false; //Downing is over *EE|?vn
boolean bStop = false; //Stop identical bgXc_>T6_y
FileAccessI fileAccessI = null; //File Access interface 2^ kn5
s.ey!ew
cFxSDTR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [r~~=b7*[
{ RA~_]Hk
this.sURL = sURL; F~P/*FFK
this.nStartPos = nStart; c$.T<r)Z
this.nEndPos = nEnd; P#9-bYNU
nThreadID = id; &`5 :GLV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lc-*8eS
} +{bh
gU*I;s>
[ 1D)$"
public void run() A'(k Yc
{ vev8l\
while(nStartPos < nEndPos && !bStop) ,XP@ pi
{ '|+=B u
m"1 ?
p!V)55J*
try{ @@xF#3
URL url = new URL(sURL); `}n0=E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1 pYsjo~
httpConnection.setRequestProperty("User-Agent","NetFox"); th;]Vo
String sProperty = "bytes="+nStartPos+"-"; F6h/0i
httpConnection.setRequestProperty("RANGE",sProperty); -y<rM0"NE
Utility.log(sProperty); GYTbeY
q .)^B@}_
"N]WL5$i
InputStream input = httpConnection.getInputStream(); 6q!7i%fK?
//logResponseHead(httpConnection); 8^NE=)cb7w
fjG/dhr
{S# 5g2
byte[] b = new byte[1024]; OQ 0b$qw
int nRead; $M%}Oz3*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2}1!WIin
{ |oB]6VS`
nStartPos += fileAccessI.write(b,0,nRead); 34^Q5B~^J
//if(nThreadID == 1) SwQOFE/Dv~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @V*au:
} U@MOvW)
$Jt8d|UP
cbY3mSfn*
Utility.log("Thread " + nThreadID + " is over!"); &s_}u%iC
bDownOver = true; 96k(XLR
//nPos = fileAccessI.write (b,0,nRead); ~c'\IM
} + >Fv*lux
catch(Exception e){e.printStackTrace ();} j=p|'`
} DDZTqsws
} qRWJ-T:!F
)Ep@$Gv|S
-1dIZy
//打印回应的头信息 yzODF>KJ
public void logResponseHead(HttpURLConnection con) : ,|=Q}
{ (u$!\fE-et
for(int i=1;;i++) c lq <$-
{ 8VKb*
String header=con.getHeaderFieldKey(i); bK6, saN>
if(header!=null) !$4Q]@ }
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9,}fx+^
Utility.log(header+" : "+con.getHeaderField(header)); G;Pt|F?c
else PP~CZ2Fze
break; yRSy(/L^+
} /<Gyg7o0
} WIhIEU7/
_q2`m
3BuD/bs
public void splitterStop() =2Pz$q*ub
{ }"!6Xm
bStop = true; i@sCMCu6
} B>c[Zg1
](idf(j
99=[>Ck)G
} \Or]5ogT'
6uv'r;U]
X:iG[iU*
/* %l0_PhAB
**FileAccess.java Z%(Df3~gmm
*//文件访问(定位，写) jTGS6{E
package NetFox; !:R^}pMhIk
import java.io.*; U]1>?,Nk'3
N GX-'w
'lSnyW{
public class FileAccessI implements Serializable{ G=+!d&mbg
R|d^M&K,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <<~lV5
RandomAccessFile oSavedFile; ^*j[&:d
long nPos; j58Dki->.
PkZf(=-X
6T5A31 Q
public FileAccessI() throws IOException %`8KG(F^
{ AiR%MD
this("",0); c=uBT K*
} j X^&4f
!c3Qcva
vgd}09y
public FileAccessI(String sName,long nPos) throws IOException loAfFK>g
{ (dw3'W
oSavedFile = new RandomAccessFile(sName,"rw"); OoA5!HEh
this.nPos = nPos; ?}!gLp
oSavedFile.seek(nPos); e\+~
} wt3Z?Pb
T/X?ZK(T
I3F6-gH
public synchronized int write(byte[] b,int nStart,int nLen) 6jQ&dN{=qB
{ ;+#za?w
int n = -1; M,=@|U/B
try{ 4OB~h]Vc
oSavedFile.write(b,nStart,nLen); ;RTrRh0v
n = nLen; 0|qx/xo|-
} ]-+.lR%vd9
catch(IOException e) &9GR2GY
{ ]y$V/Ij=qK
e.printStackTrace (); C>\h?<s
} GhchfI.
D|8sjp4
uH~ TugQ~
return n; +A.a~Stt
} @8x6#|D
3e!a>Gl*
6kmZ!9w0|
} jQw`*Y/,
0|*UeM
519:yt
/* l%Fse&4\
**SiteInfoBean.java D+@/x{wX2
*/ 7o 83|s.Bm
package NetFox; W6!4Qyn
Ra15d^
o 0cc+
public class SiteInfoBean { (,)vak&t
N";dG 3
e-duZ o
private String sSiteURL; //Site's URL DftGy:Ah3
private String sFilePath; //Saved File's Path 0wa!pE"
private String sFileName; //Saved File's Name Ot8S'cB1,$
private int nSplitter; //Count of Splited Downloading File %o_0M^3W
g)|++?
3 MI) E
public SiteInfoBean() EY[Q%
{//nSplitter的缺省值为5 Bb2r95h}^
//default value of nSplitter is 5 aZ`_W|
this("","","",5); olQ8s*
} AD4L`0D
6@Z'fT4
s5Bmv\e.i5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4jyr\=42F'
{ wshp{ y
sSiteURL= sURL; qyG636i
sFilePath = sPath; %NAFU/&
sFileName = sName; X6"^:)&1M
this.nSplitter = nSpiltter; yADN_
(w@MlMk
eL$U M
} Kr}M>hF+|
c#4L*$ViF
B$[%pm`'2
public String getSSiteURL() CFS3);'<|
{ G:6$P%.
return sSiteURL; %JA&O
} >[P7Zlwv4
ws=9u-
GVHfN5bTqn
public void setSSiteURL(String value) 2ZzD^:V[}
{ +hvIJv ?
sSiteURL = value; "!_ 4%z-
} 94k)a8-!
'|A5a+[
xvz5\s|b
public String getSFilePath() ; K 6Fe)
{ Z!=Pc$?
return sFilePath; A%czhF
} yU8Y{o;:
+]~w ?^h
8UY=}R2C
public void setSFilePath(String value) pQ-^T.'
{ LK-6z w5=(
sFilePath = value; kI[O{<kQ
} p31rhe
SAo\H
I3rnCd(
public String getSFileName() I~5fz4Q
{ O[(HE8E
return sFileName; /5'<w(
} vaCdfO&
x_iy;\s1
5\kZgXWIh
public void setSFileName(String value) bZlLivi
{ 1S.e5{
sFileName = value; 2Q'XB
} 08n%% F
P)j9\ muc
zhm!sMlO
public int getNSplitter() MfpWow-#{
{ C.e|VzQa
return nSplitter; O> ^~SO
} D>#v 6XI
iYQy#kO
f;XsShxr
public void setNSplitter(int nCount) \t(r@qq
{ a=T7w;\h
nSplitter = nCount; 0}7Rm>
} jl0Eg
} ~Z/`W`
~JRuMP
8sjHQ)<
/* 6l]?%0[*
**Utility.java Jz3<yQ-
*/ x^#{2}4u
package NetFox; I%b:Z
.dLX'84fY
e2o9)=y
public class Utility { DW%K'+@M
?9okjLp1n
BG?2PO{
public Utility() h _7;UQH
{ KA{DN!
GvtI-\h]
V5@[7ncVf
} <l s/3!
>W]"a3E
//线程睡眠 -:p1gg&
public static void sleep(int nSecond) +PXfr~ 4
{ 86 /i~s
try{ CZ%"Pqy&1L
Thread.sleep(nSecond); whZ],R*u
} GZ[h`FJg/
catch(Exception e) E=~WQ13Q
{ 4k?JxA)
e.printStackTrace (); >s?;2T2"yx
} 1Kf t?g
} lGBdQc]IL
ITqigGan%
//日志 LmdV@gR
public static void log(String sMsg) mb`}sTU).
{ w8#>xV^~
System.err.println(sMsg); \R6T"U
} R M+K":p
Nl)jQ
AS"|r
public static void log(int sMsg) [>9"RzEl
{ !4.^@^L|\
System.err.println(sMsg); "8dnFrE
} (s*Uz3sq
} 5)NfZN#&
y]r~v
>5:e1a?9
/* /,%o<Ql9
**TestMethod.java 6}lEeMRW
*/ Q>g$)-8
package NetFox; R*G>)YH
/Z_ [)PTH
dY`J,s
public class TestMethod { Ijro;rsEKM
(lsod#wEMg
7TY"{?~O5
public TestMethod() kV9NFo22
{ ///xx/weblogic60b2_win.exe /j\TmcnU^
try{ v86`\K*0Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x&b-Na3Xi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '=Y~Ir+
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3o/a8
fileFetch.start(); |i}g7
} B&j+fi
catch(Exception e){e.printStackTrace ();} .[85<"C
k6XmBBIj-
!@1!ld
} Mo|5)8_
*n?:)(
6T_c#G5
public static void main(String[] args) nW*Oo|p~=
{ zb)SlR
new TestMethod(); ]J]p:Y>NL
} 4c@F.I
} 'E8Qi'g
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