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)); ?F AsV&y
} b1nw,(hLY
for(int i=0;i<nEndPos.length-1;i++) `USR]T_`
{ 9.zy`}
nEndPos = nStartPos[i+1]; q{yz]H,
} &r~~1BnpHm
nEndPos[nEndPos.length-1] = nFileLength; $d,30hK
} B(Y{
} YwoytoXK
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//启动子线程 DXSZ#^,S[W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DG7FG--
for(int i=0;i<nStartPos.length;i++) (z ;=3S
{ <g>_#fz"K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y8m|f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C([;JO 11[
nStartPos,nEndPos,i); *3S,XMS{O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (G#)[0<fX
fileSplitterFetch.start(); pSE"]N
} <~"qz*_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T-fW[][&$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4{CVBowi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9m!4U2N,s
nEndPos = " + nFileLength); `9a%}PVQ-
// fileSplitterFetch[nPos.length-1].start(); [p}J=1S
=<`9T_S 16
T*k K-@.i
//等待子线程结束 Q!GB^P
//int count = 0; hrU.QF8
//是否结束while循环 Yi7`iC
boolean breakWhile = false; b'Mg
d";+8S
cFGP3Q4{
while(!bStop) !uO|1b
{ vq(@B
write_nPos(); "4`h -Y
Utility.sleep(500); c#u-E6
breakWhile = true; KSh<_`j
ll[U-v{
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for(int i=0;i<nStartPos.length;i++) a3R#Bg(
{ u;!CQ w/
if(!fileSplitterFetch.bDownOver) 7k+UCiu>
{ 9y.C])(2
breakWhile = false; C<qJnB:B9
break; h(GgkTj4+
} +s1+;VUs3
} /LuwPM
if(breakWhile) jTSw0\}
break; *ubLuC+b
lG%oqxJ+ L
o\b8lwA,
//count++; CN\s,. ]
//if(count>4) 1ReO.Dd`R
// siteStop(); 9WtTUk
} OR1XQij
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:!g|0CF_
System.err.println("文件下载结束！"); ^4B6IF*
} yK"U:X
catch(Exception e){e.printStackTrace ();} i @+Cr7K,
} FT`y3~
Ug3PZ7lK
-Zocu<Rs
//获得文件长度 ;#`Z(A}
public long getFileSize() f7d)
{ y'2K7\>E
int nFileLength = -1; >,uof?
try{ Xw9,O8}C7
URL url = new URL(siteInfoBean.getSSiteURL()); e)!X9><J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A ;Z%-x
httpConnection.setRequestProperty("User-Agent","NetFox"); qZ`@Ro
V)!Oss;i
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int responseCode=httpConnection.getResponseCode(); RL.%o?<&?
if(responseCode>=400) +Nc|cj
{ ?P{C=Td2z
processErrorCode(responseCode); N5%~~JRO
return -2; //-2 represent access is error EJdq"6S
} 3"I1'+
Tk.MtIs)V}
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String sHeader; 2ZIf@C{P.
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m]7Y )&3
for(int i=1;;i++) cCyg&% zsT
{ w V27
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6tzZ j:yq
//Utility.log(in.readLine()); Ujq)h:`
sHeader=httpConnection.getHeaderFieldKey(i); FE/&<g0,:
if(sHeader!=null) MSRIG-
{ -Ah\a0z
if(sHeader.equals("Content-Length")) 3w!oJB
{ wpx,~`&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )z7.S"U
break; GlQ=M)E
} (t<i?>p
} g>OGh o
else V%Y.N4H
break; Lm,io\z
} f=}u;^
} ;u}MG3Y8
catch(IOException e){e.printStackTrace ();} cpu+"/\
catch(Exception e){e.printStackTrace ();} >4LX!^V"
!Q#u i[0q
P,I3E?! j
Utility.log(nFileLength); u`E_Q8
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+n2x@ 0op
return nFileLength; ;E*^AW
} zx#d_SVi
<XCH{Te1
47$JN}qI0
//保存下载信息（文件指针位置） >s[}f6*2@
private void write_nPos() Z#7HuAF{]
{ +1h^9Y'
try{ >a_K:O|AJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1;ZEuO
output.writeInt(nStartPos.length); ?em)om
for(int i=0;i<nStartPos.length;i++) nez5z:7F
{ g.F{yX]
// output.writeLong(nPos); F^A1'J
output.writeLong(fileSplitterFetch.nStartPos); +/x|P-
output.writeLong(fileSplitterFetch.nEndPos); ;h/Y9uYn
} _IT,>#ba
output.close(); 2R<1^
} 6D0uLh
catch(IOException e){e.printStackTrace ();} ',juZ[]_{
catch(Exception e){e.printStackTrace ();} g&_0)(a\
} Sq(=Bn6E
~5p `Kg*
[}P|OCW
//读取保存的下载信息（文件指针位置） "UVV/&`o
private void read_nPos() t@4X(i0
{ 1DZGb)OU
try{ u"C`S<c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TN/I(pkt1B
int nCount = input.readInt(); L d#
nStartPos = new long[nCount]; 9&rn3hmP
nEndPos = new long[nCount]; b-~`A;pr
for(int i=0;i<nStartPos.length;i++) Szwa2IdI.
{ mUnnk`v
nStartPos = input.readLong(); yKDg ~zsh
nEndPos = input.readLong(); 2Q1* Xq{
} Zh3]bg5
input.close(); 3bE^[V8/
} }c&Zv#iO6
catch(IOException e){e.printStackTrace ();} $5il]D`
catch(Exception e){e.printStackTrace ();} }"q1B
} eYsO%y\I
W{Nhh3
'-W p|A
private void processErrorCode(int nErrorCode) Y;-"Z
{ zg8m(=k'
System.err.println("Error Code : " + nErrorCode); IXd&$h]Lq
} ~jF5%Gu
|$bZO`^
|6_<4lmTxF
//停止文件下载 pjbKMx
public void siteStop() K")-P9I6-f
{ Jc{zi^)(EN
bStop = true; 8)R)h/E>
for(int i=0;i<nStartPos.length;i++) b3Y9
fileSplitterFetch.splitterStop(); z%mM#X
xA&G91|s
:hxfd b-
} f$(w>B7..
} .>CqZN,^
//负责部分文件的抓取 {&K#~[)
**FileSplitterFetch.java p(f)u]1`
*/ 3y 0`G8P'h
package NetFox; mnu7Y([2>
E37`g}ZS
9D8el}uHf
import java.io.*; nSd?P'PFg
import java.net.*; X)~JX}-L
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public class FileSplitterFetch extends Thread { /xf%Rp4}
3ck;~Ncj<
?bN8h)>QQ8
String sURL; //File URL 173/A=]
long nStartPos; //File Snippet Start Position m[Zz(tL
long nEndPos; //File Snippet End Position +yCIA\i#t6
int nThreadID; //Thread's ID M=0I 3o}J
boolean bDownOver = false; //Downing is over TioI$?l>W(
boolean bStop = false; //Stop identical N'2u`br4KP
FileAccessI fileAccessI = null; //File Access interface fa<83<.D
[!bTko>rSB
<niHJ*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException '%K,A-7W
{ L & PhABZ
this.sURL = sURL; LuQ=i`eXx
this.nStartPos = nStart; /!7m@P|&D
this.nEndPos = nEnd; B;7L:
nThreadID = id; #C!8a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #kma)_X
} m"+9[d_u
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tLV9b %i(
public void run() yt_?4Hc"
{ o{zo-:>Jp
while(nStartPos < nEndPos && !bStop) {I(Euk>lR
{ K6|*-Wo.
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7CwG(c/5
try{ M[TgNWl/[
URL url = new URL(sURL); 7b'XQ/rs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `n5|4yaG~
httpConnection.setRequestProperty("User-Agent","NetFox"); "p$`CUtI
String sProperty = "bytes="+nStartPos+"-"; ] J:^$]
httpConnection.setRequestProperty("RANGE",sProperty); hnG'L*HooE
Utility.log(sProperty); Z;??j+`Eo
:LcR<>LZ
i~l0XjQbs
InputStream input = httpConnection.getInputStream(); $?;aW^E
//logResponseHead(httpConnection); ze,HNFg@>
,|T
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byte[] b = new byte[1024]; t;y>q
int nRead; . 6Bz48*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S ._9
{ c9f~^}jNb
nStartPos += fileAccessI.write(b,0,nRead); $&lS7}
//if(nThreadID == 1) h'kgL~+$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #^Sd r-
} :ykQ[d`:|
+s_@964
r 97 VX>
Utility.log("Thread " + nThreadID + " is over!"); O]lWaiR`
bDownOver = true; Q[8L='E
//nPos = fileAccessI.write (b,0,nRead); n*bbmG1
} KvktC|~?
catch(Exception e){e.printStackTrace ();} M}M.
} qw"`NubX
} :5h&f
l'-iIbKX
ogjm6;
//打印回应的头信息 (x?A#o>%
public void logResponseHead(HttpURLConnection con) \JN<"/
{ ,bJZs-P0
for(int i=1;;i++) e&]XiV'
{ "t4~xs`~X
String header=con.getHeaderFieldKey(i); QLIm+)T
if(header!=null) s u![ST(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dsJ}C|N
Utility.log(header+" : "+con.getHeaderField(header)); $WTu7lVV[1
else #2x\d
break; b6);bX>e
} 8(uxz84ce
} n;O 3.2
DB%=/ \U
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public void splitterStop() 4*m\Zoq>
{ E})PNf;
bStop = true; C{Aeud #5
} y>Nlj%XH
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} ?]$.3azO
Ct #hl8b:
#T !YFMh;
/* |{ *ce<ip5
**FileAccess.java }$g5:k!
*//文件访问(定位，写) ?^,GaZ^V
package NetFox; T[ky7\
import java.io.*; /mqEc9sq,
SU H^]4>
8!:4m"Y
public class FileAccessI implements Serializable{ nLo:\I(
mN~;MR;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C5;"mo-
RandomAccessFile oSavedFile; 7xWX:2l*?
long nPos; #4~Ivj
bumS>:
!m]76=@
public FileAccessI() throws IOException >I!dJH/gj
{ e2/[`k=7-
this("",0); pMs%`j#T
} :/ "qNPJ
,uDB]
l^"gpO${K
public FileAccessI(String sName,long nPos) throws IOException Kd^ ._
{ 9J l9\y9
oSavedFile = new RandomAccessFile(sName,"rw"); PJkEBdM.
this.nPos = nPos; o7hjx hmC
oSavedFile.seek(nPos); ))306*X\
} o.y4&bC14;
^H&6'A`
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public synchronized int write(byte[] b,int nStart,int nLen) H( cY=d,
{ #?8'Z/1)
int n = -1; [.3M>,)+-
try{ 7!L"ef62o
oSavedFile.write(b,nStart,nLen); NV*t
n = nLen; ,4EE9 ?J
} 5TzMv3;in2
catch(IOException e) kO/dZ%vj
{ ob-be2EysH
e.printStackTrace (); `?`\!uP"
} ?vM{9!M
Hyc19|
W)j/[
return n; ;QW)tv.y
} 3%k@,Vvt
FnL~8otPF'
|A0kbC.
} 3osAWSCEL
okr'=iDg
5b|_?Em7
/* //|9J(B]
**SiteInfoBean.java >&BgF*mm
*/ P+oCcYp
package NetFox; ]NsbV
X8?|5$Ey
4sROMk=l
public class SiteInfoBean { [+ 1([#
)mp0k%
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private String sSiteURL; //Site's URL WS2TOAya)
private String sFilePath; //Saved File's Path YwHnDVV+
private String sFileName; //Saved File's Name q$U;\Mg)
private int nSplitter; //Count of Splited Downloading File oX!s u
-OVJ]
}7Pd\tG]
public SiteInfoBean() >Li ~Og@
{//nSplitter的缺省值为5 rZGA9duy
//default value of nSplitter is 5 =cqaA^HQL
this("","","",5); ZLo3 0*
} sveFxI
tA'i-D&
Q/0;r{@Tq}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ezHj?@
{ Nb(se*Y#
sSiteURL= sURL; )lH?XpfTjm
sFilePath = sPath; `(Ei-$ >U&
sFileName = sName; 6n;ewl}
this.nSplitter = nSpiltter; @(Q4
&X +@,!
sOVaQ&+y
} jZ.+b j >
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public String getSSiteURL() +.[#C5
{ gy~M]u{
return sSiteURL; q;Qpd]H
} ]Jv Z:'g}
.L6t3/^
7.akp
public void setSSiteURL(String value) )M^;6S
{ GTJ\APrH
sSiteURL = value; C,jPr )6)
} R)G'ILneV
9Q].cDe[
YQe @C
public String getSFilePath() LOe!qt\&
{ ,CwhpW\Y
return sFilePath; ;2%3~L8?V
} [y>Q3UqN
/rJvw
9.PY49|
public void setSFilePath(String value) ;41s&~eR
{ mQ' ]0DS
sFilePath = value; rPr#V1}1a
} rA{h/T"
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KasOh"W.P
public String getSFileName() +Y 3_)
{ h'T\gF E%
return sFileName; UDuKG\_J<y
} WDgp(Av!
,gD30Pylz
mX,#|qLf
public void setSFileName(String value) } vcr71u
{ ZOS{F_2.
sFileName = value; 1&wZJP=
} t41\nTZr
ki}Uw#
G|Q}.v
public int getNSplitter() 8>O'_6Joj
{ TvM{ QGN
return nSplitter; VwtGHF'
} c.jnPVf:
_FAwW<S4B
T /[)U
public void setNSplitter(int nCount) B(b[Dbb
{ {jlm]<:&Z
nSplitter = nCount; ?;uzx7@F
} .[K{;^>
} 9HP)@66
EKwS~G.b!
X(Ef=:
/* )Q7;)iPY#
**Utility.java {"4t`dM
*/ gxt2Mq;q~}
package NetFox; SHz& o[u
eb.`Q+Gb
MV=.(Zs
public class Utility { 5dYIL`
7 yF#G9,
EEaKT`/d
public Utility() /R@(yT=t
{ <|.S~HLTQ
@LwhQ
2evM|Dj
} ^{Syg;F=
XXe7w3x{
//线程睡眠 ( B50~it
public static void sleep(int nSecond) !?Ow"i-lp
{ _k6N(c2Nd
try{ 4Ag+
Thread.sleep(nSecond); U.>n]/&
} ,9W0fm\t
catch(Exception e) QHtpCNTVb
{ -pX/Tt6
e.printStackTrace (); 5zEl`h
} eaF5S'k 4$
} V @d:n
P[gk9{sv
//日志 QC ]z--wu
public static void log(String sMsg) w8>T ~Mv
{ 7d'@Z2%J0
System.err.println(sMsg); hM>xe8yE
} vuw1ycy)
)xTp7YnZ;
bh+R9~
public static void log(int sMsg) }8x[
{ A$1pMG~as
System.err.println(sMsg); Y]P $|JW):
} y>wr $
} D8Ni=.ALL
I`5MAvP
+{Q\B}3cj1
/* i<%(Z[9Lk
**TestMethod.java .dM 0
*/ /a9+R)Al
package NetFox; \a|gzC1G
2.; OHQTE
.l#Pmd!
public class TestMethod { _KD(V2W
ijoR(R^r
+86\&y)
public TestMethod() .:<c[EJ b
{ ///xx/weblogic60b2_win.exe dcXtT3,kpX
try{ i37W^9 R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !pDS*{)E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *sL'6"#Cre
SiteFileFetch fileFetch = new SiteFileFetch(bean); +.>O%pNj
fileFetch.start(); z!RA=]3h
} Z39^nGO
catch(Exception e){e.printStackTrace ();} >1joCG~
3zh'5qQ
Q[~O`Lz
} p&ow\AO
P#EqeO
'n>|jw)
public static void main(String[] args) %f:'A%'Qb
{ g:f0K2)\r:
new TestMethod(); q:?g?v
} 0imz}Z]
} uy`U1>
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