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)); \%PaceH
} 1XM^8 .;
for(int i=0;i<nEndPos.length-1;i++) ku$$ 1xq
{ S}APQ
nEndPos = nStartPos[i+1]; JD@J[YY5R
} Tc8un.
nEndPos[nEndPos.length-1] = nFileLength; N\:. M
} eP*lI<NQ1
} { eCC$&"
m'P1BLk
J)P$2#
//启动子线程 /VmR<C?h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R\o<7g-|
for(int i=0;i<nStartPos.length;i++) yFDv6yJ.
{ 2gO2jJlv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IDnC<MO>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >:D j\"o
nStartPos,nEndPos,i); 'cY` w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o-}R?>
fileSplitterFetch.start(); :ba5iMa
} 2M#r]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 311LC cRp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :Ad&$eg+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t#q<n:WeYU
nEndPos = " + nFileLength); pZ/>[TP(%F
// fileSplitterFetch[nPos.length-1].start(); !rqF}d
/~x"wo
EEGy!bff
//等待子线程结束 f B9;_z
//int count = 0; KII *az
//是否结束while循环 R|wGU)KEc'
boolean breakWhile = false; _.L4e^N&UO
<n]x#0p
3p0LN'q]A
while(!bStop) %Gt.m
{ PRz/inru-
write_nPos(); _YcA+3ZL
Utility.sleep(500); v\p;SwI
breakWhile = true; \&H nKhI
M5xCC!
2W4qBaG$=
for(int i=0;i<nStartPos.length;i++) @)Ofi j
{ jBegh9KHq
if(!fileSplitterFetch.bDownOver) fk_o@ G!0
{ sQMFpIrr
breakWhile = false; DGzw8|/(
break; ,3@#F/c3i~
} In`mtn q
} FJasS8
if(breakWhile) *Z|y'<s
break; y@\V+
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qWmQ-|Py
//count++; "~D]E7Q3y
//if(count>4) I1PuHf Qs
// siteStop(); xQUu|gtL4
} !Q#{o^{Y~
m=YU2!Mb
K_dOq68_
System.err.println("文件下载结束！"); DZi!aJ
} o865(<p
catch(Exception e){e.printStackTrace ();} 5}`_x+$%(`
} _-EyT
3YVi" k?2
-|E!e.^7:
//获得文件长度 ;VWAf;U;B
public long getFileSize() $sEy%-
{ Uw47LP
int nFileLength = -1; St e=&^
try{ ih7/}
URL url = new URL(siteInfoBean.getSSiteURL()); 9(@\&>)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XGl+S
httpConnection.setRequestProperty("User-Agent","NetFox"); mvq&Pj 1}L
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:s4p/*f
int responseCode=httpConnection.getResponseCode(); b,CaWg
if(responseCode>=400) 7D<#(CE{
{ ]MxC_V+P`
processErrorCode(responseCode); {7)st W
return -2; //-2 represent access is error Z,=7Tu bR#
} Y'ow
B[KJR?>
aoXb22]{
String sHeader; mya_4I m
;Rv!k&Df
/kfgx{jZ
for(int i=1;;i++) ['T:ea6B
{ C+TI]{t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P'`r
//Utility.log(in.readLine()); )a-Du$kd
sHeader=httpConnection.getHeaderFieldKey(i); "sG=wjcw^
if(sHeader!=null) ariLG [:X
{ nJo`B4'U
if(sHeader.equals("Content-Length")) .C--gQpIv
{ (;q;E\Ejq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zzyHoZJP
break; ({q?d[q[
} 6q{HU]N+
} Bro9YP4<
else B&@?*^.
break; R00eisd
} )BwjZMJ.N
} ?O8ViB?2
catch(IOException e){e.printStackTrace ();} Z-l=\ekJ
catch(Exception e){e.printStackTrace ();} PS[+~>%
mFi&YpHu3
%T~ig[GstX
Utility.log(nFileLength); 6Aku1h
tQjLOv+?=
@~%r5pz6
return nFileLength; =F@Wgn,
} (JM5`XwM
GSRVe/[
!7kG!)40
//保存下载信息（文件指针位置） O)jWZOVp >
private void write_nPos() ,]d,-)KX8
{ gntxNp[9T
try{ 3de_V|%
output = new DataOutputStream(new FileOutputStream(tmpFile)); /bi}'H+#
output.writeInt(nStartPos.length); sIxTG y.
for(int i=0;i<nStartPos.length;i++) ;LMJd@
{ pim!.=vN/U
// output.writeLong(nPos); #H:7@
output.writeLong(fileSplitterFetch.nStartPos); hy`?E6=9+
output.writeLong(fileSplitterFetch.nEndPos); gy_>`16K
} /\hzb/
output.close(); HbxL:~:}J
} m8o(J\]
catch(IOException e){e.printStackTrace ();} ]]*7\ :cb
catch(Exception e){e.printStackTrace ();} *#C+iAF|)'
} lk( }-
v~^{{O
$GTU$4u
//读取保存的下载信息（文件指针位置） 1#ft#-g}
private void read_nPos() @9lUSk^9
{ eb=D/
try{ #':fkIYe'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7BJzMlJ1Y
int nCount = input.readInt(); QC9eUYe
nStartPos = new long[nCount]; o<|P9#(U"
nEndPos = new long[nCount]; }3OKC2K~
for(int i=0;i<nStartPos.length;i++) W;,C_
{ 6Q${U7%7
nStartPos = input.readLong(); y$_eCmq
nEndPos = input.readLong(); "\3B^ e,
} egq67S
input.close(); E/%9jDTQ
} u)~C;f)
catch(IOException e){e.printStackTrace ();} zc;|fHW~O
catch(Exception e){e.printStackTrace ();} E<Q f!2s$
} RH&~+5
i*@<y/&'
iT%} $Lu~
private void processErrorCode(int nErrorCode) G{6;>8h
{ K5xX)oV
System.err.println("Error Code : " + nErrorCode); ~1>.A(,=z
} :R~MO&
k@z,Iq8
!lj| cT9
//停止文件下载 PEW=@xj2y
public void siteStop() 'LE=6{#
{ jW 3c"
bStop = true; LILQ\I<<'
for(int i=0;i<nStartPos.length;i++) 3GUZ;jdn
fileSplitterFetch.splitterStop(); 3U7*>H
C,v(:ZE$J7
vy\RcP
} &M.66O@
} DF*:_B)
//负责部分文件的抓取 ,f[>L|?e
**FileSplitterFetch.java OHhsP}/
*/ +Zaj,oEE
package NetFox; T Kg aV;92
rV T{90,
,uSQNre\j
import java.io.*; -@0GcUE:r
import java.net.*; *U P@9D
EV*IoE$W]=
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public class FileSplitterFetch extends Thread { @n{JM7ctJ
u[DfzH
N-e @j4WU
String sURL; //File URL IX>d`O61*g
long nStartPos; //File Snippet Start Position \uaJ@{Vug
long nEndPos; //File Snippet End Position <gQIq{B?
int nThreadID; //Thread's ID IrqZi1
boolean bDownOver = false; //Downing is over O vk_\On
boolean bStop = false; //Stop identical GJoS#s
FileAccessI fileAccessI = null; //File Access interface Z2'Bk2 L
0 g?z&?
d~JKH&x<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jAm3HI
{ +PcmJ
this.sURL = sURL; PqiB\~o@Z
this.nStartPos = nStart; T^Ze3L]
this.nEndPos = nEnd; 9Ru8~R/\
nThreadID = id; nv~%#|v_W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8[E!E)4M
} r}mbXvn
=9fajRFTt
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public void run() f]\CD<g3|E
{ R'!
while(nStartPos < nEndPos && !bStop) /XzH?n/{R
{ ,Q HU_jt
IHcD*zQ
9mmCp&~Z
try{ B#.L
URL url = new URL(sURL); b"#WxgaF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y}#J4i0b*
httpConnection.setRequestProperty("User-Agent","NetFox"); QT>`^/]d
String sProperty = "bytes="+nStartPos+"-"; U8LtG/
httpConnection.setRequestProperty("RANGE",sProperty); G"Sd@%W(
Utility.log(sProperty); er!DYv
:[hgxJu+
+/)#( j@
InputStream input = httpConnection.getInputStream(); S|]X'f
//logResponseHead(httpConnection); b-{=s+:
?C&z]f3(:
K0}pi+=
byte[] b = new byte[1024]; JU^lyi!
int nRead; ]Zyur`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w[IE
{ RIY,K*f.
nStartPos += fileAccessI.write(b,0,nRead); T`;%TO*Y
//if(nThreadID == 1) 8(~K~q[Cr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %\H|B0
} `m!j$,c.
k=4N.*#`y
CkdP#}f
Utility.log("Thread " + nThreadID + " is over!"); ^7 &5 z&o
bDownOver = true; PGLplXb#[S
//nPos = fileAccessI.write (b,0,nRead); ~s]iy9i
} RHO(?8"_
catch(Exception e){e.printStackTrace ();} 2E)wpgUc?e
} s0k`p<q
} n1VaLD
CB/D4j;
9Bw|(J
//打印回应的头信息 5 ({t4dm
public void logResponseHead(HttpURLConnection con) .MJofE;Jn
{ ^wc"&;=c|
for(int i=1;;i++) (<}&DE
{ /q5v"iX]T
String header=con.getHeaderFieldKey(i); 37|&?||
if(header!=null) ak |WW]R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z2QP)150
Utility.log(header+" : "+con.getHeaderField(header)); g'V>_u#(
else -1UD0(
break; D-4f >
} 7zSLAHW
} NT+?#0I
Z^IPZF
#>mr[
public void splitterStop() Qg[/%$x.
{ ;[u%_
bStop = true; obNqsyc77R
} p|&Yku=
2L} SJUk*
g#t[LI9(F[
} }7 c[Q($K
\V*xWS
.5y+fL
/* 1r]IogI
**FileAccess.java gm[z[~X@
*//文件访问(定位，写) {yB&xj[z
package NetFox; aM:nOt" S1
import java.io.*; $l|qk z
"vyNxZE
aW`Lec{.
public class FileAccessI implements Serializable{ c;n *AK
'-"/ =j&d[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j"'(sW-
RandomAccessFile oSavedFile; m|:_]/*qE
long nPos; !=:$lzS^
/x[jQM\
7|[mz> "d
public FileAccessI() throws IOException @>)r}b
{ yX0dbW~@y
this("",0); ,H19`;Q
} Wu_kx2h
9)gC6IiW
LG1r]2
public FileAccessI(String sName,long nPos) throws IOException )Hk3A$6(
{ %^>ju;i^O
oSavedFile = new RandomAccessFile(sName,"rw"); !Y\D?rKZ
this.nPos = nPos; <RG|Dx[:=
oSavedFile.seek(nPos); DFd%9*N
} NF0%}II&xK
o)2W`i&
)8UWhl=
public synchronized int write(byte[] b,int nStart,int nLen) AbYqf%~7`l
{ ZObhF#Y9
int n = -1; t{WzKy
try{ O2BDL1o
oSavedFile.write(b,nStart,nLen); naw0$kXTA
n = nLen; fI~Xmw+}}
} Ts ^"xlK
catch(IOException e) P}TI q#
{ mHBnC&-/
e.printStackTrace (); T<w5vqFDu
} qASqscO
uec!RKE
uJ5Eka
return n; m:WyuU<
} ,eZ1uBI?
QiLEL
%d(^d
} .%Ta]!0
X~<("
w`il=ZAC
/* e*;c(3>(
**SiteInfoBean.java ulkJR-""&
*/ /U"CO8Da
package NetFox; eL\;Nf+Zp
>ey\jDr#O
43Qtj$F
public class SiteInfoBean { 7qg{v9|,
]jaQ[g$F
P3nb2.
private String sSiteURL; //Site's URL q&/Yg,p\
private String sFilePath; //Saved File's Path NNE<L;u
private String sFileName; //Saved File's Name V%YiAr>
private int nSplitter; //Count of Splited Downloading File IS#FiH
zOqn<Y@
!>e5z|1
public SiteInfoBean() }c`fW&
{//nSplitter的缺省值为5 X(\fN[;
//default value of nSplitter is 5 weE/TW\e
this("","","",5); UF<uU-C"
} fe_yqIdk
$n+w$CI)
;ml)l~~YU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LK, bO|
{ Pp`*]Ib
sSiteURL= sURL; bVL9vNK
sFilePath = sPath; 3plzHz,x
sFileName = sName; 'C ~y5j
this.nSplitter = nSpiltter; 8-_QFgY
_&j}<K$-(
_`_%Y(Xat
} w - Pk7I
'eJ+JM<0%
bD[!/'4eJ
public String getSSiteURL() M5*{
{ I{lT>go
return sSiteURL; ,>:;#2+og
} #L{OV)a<
3'c0#h@VD
N\#MwLm
public void setSSiteURL(String value) k7>|q"0C
{ kRTwaNDOD
sSiteURL = value; -x'z XvWZ
} 839IRM@'5
qZh1`\G
;IVDr:
public String getSFilePath() 8ZKo_I\
{ ~d%Pnw|
return sFilePath; FFH_d <q
} NDs!a
niqN{
`xywho%/Y
public void setSFilePath(String value) gOr%!QaF
{ `S2[5i
sFilePath = value; 8g:;)u4$P
} BVr0Gk
Gu'rUo3Do
Pj4/xX
public String getSFileName() h~p>re
{ o4%y>d)
return sFileName; )EL!D%<A
} >layJt
+> WM[o^I
AwTJJ0>
public void setSFileName(String value) "v`
{ Z7_ zMM
sFileName = value; )E,\H@A
} y-j\zK
rc/nFl6#
8:#rA*Y
public int getNSplitter() Pp|*J^U 4
{ ;Wl+zw
return nSplitter; *_KFW@bC:
} CWNx4)ZGw
8S<@"v
B?)@u|0
public void setNSplitter(int nCount) raCi 8
{ m^#rB`0;L
nSplitter = nCount; d ,Y#H0`
} &CIVL#];e
} un=2}@ '
+q)5dYRzV
n#:N;T;\a
/* K\$J4~EtG
**Utility.java a9T@$:
*/ Ma\Gb+>
package NetFox; e+j)~RBnu3
\N4 y<
U R%4@
public class Utility { '2laTl]`
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A5H3%o(6k
public Utility() #fL8Kq
{ \igmv]G%
G <uyin>
GQl$yZaK{
} +8#_59;x
y8 KX<2s1
//线程睡眠 XO9M_*Va
public static void sleep(int nSecond) S_T1y
{ ]a!xUg!S
try{ 1|?05<8
Thread.sleep(nSecond); ! /NG.Wf
} J%jB?2 1:o
catch(Exception e) c= x,ijY "
{ :T._ba3|
e.printStackTrace (); v\,N5
} ,i0b)=!o
} gi-Yqco
=r.mlc``W
//日志 }->.k/vc
public static void log(String sMsg) #_|sgS?1
{ K3' niGT
System.err.println(sMsg); rC7``#5
} 2<][%> '
F! X}(N?t
+E;2d-x*p
public static void log(int sMsg) sU"}-de
{ h@@nR(<i
System.err.println(sMsg); eXkujjSw"
} (__yh^h:m
} 7;tJK^J`
#CnHf
nD0}wiL{
/* I0'[!kBF|
**TestMethod.java T /mI[*1xI
*/ iajX~kv
package NetFox; L3p`
78Aa|AJU
UDc$"a}ds{
public class TestMethod { /\w)>0
R'dSbn
'r@:Cz3e*I
public TestMethod() qU,c~C=Qf
{ ///xx/weblogic60b2_win.exe eVR5Xar
try{ v$)q($}p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yyfq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g!`3{ /4
SiteFileFetch fileFetch = new SiteFileFetch(bean); AWjm~D-?
fileFetch.start(); oM)h#8bq
} bO;(bE m@
catch(Exception e){e.printStackTrace ();} ~=wCwA|1
qTB$`f'|$
HJC(\\~
} =rd|0K"(r
4#(ZNP
9~0^PzTA
public static void main(String[] args) ;ml 3
{ `T2$4>!
new TestMethod(); #$1og=
} kip`Myw+
} W{5:'9,
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