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)); 5hhiP2q
} /*V:Lh
for(int i=0;i<nEndPos.length-1;i++) 2s^9q9NS"
{ gY],U4_:p
nEndPos = nStartPos[i+1]; R*"31&3le4
} OpNTyKbaD
nEndPos[nEndPos.length-1] = nFileLength; |"K<
} 1v<,nABuJ6
} sIVVF#0}]
cWNZ +Q8Y
]JQ+*ZYUE
//启动子线程 ;)6LX-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T(GEFntY
for(int i=0;i<nStartPos.length;i++) bF85T(G
{ .=~-sj@k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qD/GYqvm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t;3n
nStartPos,nEndPos,i); fXL&?~fS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QU#u5sX A
fileSplitterFetch.start(); iY|zv|;]=
} Z+gG.|"k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '8k{\>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '7Ad:em
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^R g=*L
nEndPos = " + nFileLength); ^|b]E
// fileSplitterFetch[nPos.length-1].start(); [!g$|
iXF iFsb
z: ;ZPSn
//等待子线程结束 +qWrm|O]
//int count = 0; ~PTqR2x
//是否结束while循环 gv6}GE
boolean breakWhile = false; @]{+9m8G@
IIZu&iZo\
wsfN \6e
while(!bStop) |9fvj6?Y
{ fGwRv%$^
write_nPos(); _mEW]9Sp
Utility.sleep(500); 0xN1Xm0d
breakWhile = true; W[$GB_A)
=DL |Q
: \{>+!`w
for(int i=0;i<nStartPos.length;i++) =7e|e6
{ 4!q4WQ ;
if(!fileSplitterFetch.bDownOver) .wdWs tQ
{ !nm[ZrSP
breakWhile = false; I^u$H&
break; !,SGKLs.m
} A"Prgf eT
} Fm{/&U^
if(breakWhile) 4s:S_Dw
break; @|=JXSr!KY
O<*l"fw3
b`9J1p.;
//count++; ,k9@%{4 l
//if(count>4) ,mHQ
// siteStop(); j;BMuLTm1
} 7U3b YU~;
@5[9iY
Tc3~~X
System.err.println("文件下载结束！"); J2KULXF
} Au=9<WB%H
catch(Exception e){e.printStackTrace ();} Q#h*C ZT
} `U.VfQR:
u%s@B1j
vMlT
//获得文件长度 g?9IS,Gp
public long getFileSize() \ZOH3`vq
{ lDWg%pI+
int nFileLength = -1; ^xNs^wC.
try{ ,A{'lu
URL url = new URL(siteInfoBean.getSSiteURL()); *GGiSt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I,nW~;OV0
httpConnection.setRequestProperty("User-Agent","NetFox"); ?*nFz0cs^
21LJ3rW_
W1$<,4j@M
int responseCode=httpConnection.getResponseCode(); HCCEIgCT
if(responseCode>=400) &|'t>-de,
{ lMQ_S"
processErrorCode(responseCode); <*Ex6/j
return -2; //-2 represent access is error |e%o
} &A1~x!`
>l>;"R9N
}|Ao@UvH
String sHeader; 4t]YHLBS
_Yms]QEZ
}+m")=1{
for(int i=1;;i++) Sc?UjEs
{ 2~wIHtd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3jh: K
//Utility.log(in.readLine()); #+Pk_?
sHeader=httpConnection.getHeaderFieldKey(i); O} &%R:
if(sHeader!=null) nZtP!^#
{ q!OB?03n
if(sHeader.equals("Content-Length")) ]zt77'J
{ {\P`-'C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IQm[,Fh
break; Twi7g3}/jB
} r](%9Y
} 7<Yf
else L3@upb
break; %77X/%.Y
} $*k9e^{S
} '=V!Y$tn
catch(IOException e){e.printStackTrace ();} rD?G7l<~>_
catch(Exception e){e.printStackTrace ();} q!y6K*
:|5\XV)>
Rn4Bl8z'>
Utility.log(nFileLength); jMAZ4M
?b,x;hIO
jfOqE*frl!
return nFileLength; KT9!R
} *Bm7>g6
C@ns`Eh8w
zT< P_l
//保存下载信息（文件指针位置） ~Q3y3,x
private void write_nPos() CC~:z/4,N
{ wr~Ydmsf
try{ *?o`90HHP[
output = new DataOutputStream(new FileOutputStream(tmpFile)); c?/R=/H
output.writeInt(nStartPos.length); |n/qJIE6
for(int i=0;i<nStartPos.length;i++) !4 =]@eFk
{ pVa9g)+z}
// output.writeLong(nPos); ,SQ`, C _5
output.writeLong(fileSplitterFetch.nStartPos); ]}za
output.writeLong(fileSplitterFetch.nEndPos); JK/VIu&!
} }iE!( l
output.close(); *%#Sa~iPo
} zF([{5r[!)
catch(IOException e){e.printStackTrace ();} q-lejVS(g
catch(Exception e){e.printStackTrace ();} ?r}'0dW
} YR? ujN
bZKlQ<sI
6]D%|R,Q#}
//读取保存的下载信息（文件指针位置） h@H8oZ[
private void read_nPos() iu$:_W_
{ |ler\"Eu
try{ ^F?}MY>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .m^L,;+2
int nCount = input.readInt(); e%wzcn
nStartPos = new long[nCount]; Fs}vI~}
nEndPos = new long[nCount]; MKPw;@-
for(int i=0;i<nStartPos.length;i++) d7 W[.M$]
{ vhz[H
nStartPos = input.readLong(); U%?
nEndPos = input.readLong(); A{IJ](5.kd
} `Jv~.EF%
input.close(); >[A7oH
} .G~Y`0
catch(IOException e){e.printStackTrace ();} _s%;GWj
catch(Exception e){e.printStackTrace ();} [WXa]d5Y
} x[dR5
YKV?I
Zai:?%^
private void processErrorCode(int nErrorCode) Gp.XTz#=
{ G<_<j}=
System.err.println("Error Code : " + nErrorCode); Q&k1' nT5
} -L6YLe%w
=uil3:,[S
&9ZrZ"]
//停止文件下载 sPxDo?1x-
public void siteStop() U{[ g"_+~
{ "+{>"_KV
bStop = true; 9ZVzIv(
for(int i=0;i<nStartPos.length;i++) >bUxb-8
fileSplitterFetch.splitterStop(); ,g~Iup
Kwmtt
m~;}8ObQE
} R<eD)+
} "WfVZBWG$
//负责部分文件的抓取 5%#V>|@e#
**FileSplitterFetch.java nPRv.h
*/ f[s|<U^
package NetFox; gbvMS*KQz
rFLm!J]
,VYUQE>\
import java.io.*; ^Q9;ro*;ck
import java.net.*; ~^<1k-
I8%Uyap{
!$Whftg
public class FileSplitterFetch extends Thread { ~e;2gm
0tS< /G8
j0q:i}/U,
String sURL; //File URL {Yc#XP
long nStartPos; //File Snippet Start Position QMQ\y8E
long nEndPos; //File Snippet End Position e{6I-5`|,#
int nThreadID; //Thread's ID ygo4.
boolean bDownOver = false; //Downing is over - xE%`X
boolean bStop = false; //Stop identical 7mBH#Q)
FileAccessI fileAccessI = null; //File Access interface g=)OcTd#
E-v#G~
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bZ-_Q
{ HD~o]l=H
this.sURL = sURL; L}hc|(:
this.nStartPos = nStart; ODFCA. t
this.nEndPos = nEnd; 5==hyIy
nThreadID = id; DV!10NqUr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @ i*It Hk
} pW,)yo4
(O-.^VV
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public void run() jnzOTS
{ 9=5xt;mEs}
while(nStartPos < nEndPos && !bStop) /!A?>#O&.
{ f j:q>}V
{W11+L{8
O =gv2e
try{ ]*v[6 +
URL url = new URL(sURL); GC3WB4iY@U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SCq:jI
httpConnection.setRequestProperty("User-Agent","NetFox"); }v4T&/vt-
String sProperty = "bytes="+nStartPos+"-"; <_>xkQbn2
httpConnection.setRequestProperty("RANGE",sProperty); VOkSR6
Utility.log(sProperty); Gv\:Agi
I ]HP
*/)O8`}2
InputStream input = httpConnection.getInputStream(); )[np{eF.k
//logResponseHead(httpConnection); {7Qj+e^
yLgv<%8f
oU)Hco"_k
byte[] b = new byte[1024]; 5i1E 5@~
int nRead; (,XbxDfM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VBq|j"o0"
{ g5@P
nStartPos += fileAccessI.write(b,0,nRead); kesuM3
//if(nThreadID == 1) C;\R 62'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 66C_XT
} 2kkqPBc_
!L3\B_#
wi-F@})f#
Utility.log("Thread " + nThreadID + " is over!"); ]rS:#LK
bDownOver = true; WvN{f*
//nPos = fileAccessI.write (b,0,nRead); i1JVvNMQ,
} 0?Bv zfb
catch(Exception e){e.printStackTrace ();} {g7~e{2
} OSY.$$IO
} _uq[D`=
:x[SV^fw[
X0 ^~`g
//打印回应的头信息 EN/r{Cm$B
public void logResponseHead(HttpURLConnection con) mhW*rH*m
{ }Hy4^2B
for(int i=1;;i++) /*1p|c^
{ #t<
String header=con.getHeaderFieldKey(i); r0/aw
if(header!=null) )F'r-I%Hi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 77H"=
Utility.log(header+" : "+con.getHeaderField(header)); :um]a70
else .X\9vVJ
break; z]HaE|j}S
} 1{-yF :A
} bR'UhPs-8;
K:q|M?_
Y|nC_7&Bv
public void splitterStop() r?2J
{ ` #; "
bStop = true; &j?+%Y1n@
} S~hoAl"xb/
l}_6_g>6
oxNQNJ!X
} ,lDOo+eE%:
&2sfu0K
?)O!(=6%'
/* 0)]?@"j
**FileAccess.java {NUI8AL46A
*//文件访问(定位，写) ["WWaCcx
package NetFox; U28frRa
import java.io.*; "_ H9]}Q
tLzb*U8'1w
:$Xvq-#$|
public class FileAccessI implements Serializable{ Vb,'VN%
x(7Q5Uk\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 td5! S]
RandomAccessFile oSavedFile; ows3%
long nPos; (>C$8)v
|ngv{g
{F ',e~}s
public FileAccessI() throws IOException #CRd@k?
{ ymb{rKkN3
this("",0); m[qW)N:w
} x5R|,bY
_sK{qQxvM=
pEq }b+-
public FileAccessI(String sName,long nPos) throws IOException in7h^6?I
{ 2" u,f
oSavedFile = new RandomAccessFile(sName,"rw"); PW+B&7{
this.nPos = nPos; 0]xp"xOwW
oSavedFile.seek(nPos); |ITh2m
} f~:wI9
gMsB1|
Z '~Ie~
public synchronized int write(byte[] b,int nStart,int nLen) j:7AVnt
{ u;9a/RI
int n = -1; (*Z:ByA
try{ ?T)M z q}
oSavedFile.write(b,nStart,nLen); X16vvsjw5
n = nLen; l#TE$d^ym
} "t%Jj89a\
catch(IOException e) F^CR$L& K
{ t!\B6!Fo
e.printStackTrace (); &3 *#h
} Gq-~zmg
(,D:6(R7t
Xi0fX$-,
return n; g(dReC
} ;)q"X>FMZe
-8yN6 0|
hv*XuT/
} r7FpR!
"R]wPF5u
'"T9y=9]s
/* 8cGoo u6
**SiteInfoBean.java Ey)ey-'\
*/ D2I|Z
package NetFox; 0UhJ I
%D3Asw/5a
Jwpc8MQ
public class SiteInfoBean { %+oqAYm+s
Hu+GN3`sx^
O9rA3qv B
private String sSiteURL; //Site's URL sGx3O i
private String sFilePath; //Saved File's Path 5zz">-Q !
private String sFileName; //Saved File's Name >qZl s'
private int nSplitter; //Count of Splited Downloading File 3)y=}jw
06z+xxCo
aSMoee@!
public SiteInfoBean() c7D{^$L9v
{//nSplitter的缺省值为5 z9E*1B+
//default value of nSplitter is 5 <R?S
this("","","",5); zKT4j1h
} [qU`}S2
J,J6bfR/
CA5T3J@vAQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a n0n8l
{ $'<FPbUtD}
sSiteURL= sURL; }Fsr"RER@{
sFilePath = sPath; T+oOlug
sFileName = sName; B!U;a=ia
this.nSplitter = nSpiltter; 5A+@xhRf
*T~b ox
1024L;
} e.fxB
&+3RsIlW
H5*#=It
public String getSSiteURL() 5_1\{lP
{ biV NZdA
return sSiteURL; FKUo^F?z
} BjGfUQ
q:=jv6T#
Dus!Ki~8(t
public void setSSiteURL(String value) ozKS<<
{ Mh MXn;VKj
sSiteURL = value; fL*+[v4
} }<zbx*!
+S WtHj7e
]Ljb&*IEj
public String getSFilePath() {< EPm&q
{ Ze <)B *
return sFilePath; iNc!zA4
} Yr>0Qg],
b1;h6AeL
-/2B fIq
public void setSFilePath(String value) @$iZ9x6t
{ = 5[%%Lf
sFilePath = value; nw_s:
} 0f@9y
6)BPDfU,
o2cc3`*8d
public String getSFileName() 7!wc'~;
{ P- +]4\
return sFileName; R x(yn
} ;G[0%z+*
;WAa4r>
,.h@tN<C
public void setSFileName(String value) EwmNgmYq
{ I9m9`4BK
sFileName = value; /;{L~f=et)
} u-tD_UIck
sVGQSJJ5
0 /9 C=v
public int getNSplitter() #c":y5:
{ +25=u|#4r
return nSplitter; \98N8p;,I
} Djdd|Z+*{
v??$z#1F3
"Q:h[)a
public void setNSplitter(int nCount) z`.<dNg
{ '$eJATtC
nSplitter = nCount; {> 8?6m-
} Z/!awf>
} xR8.1T?8
c{ +bY.J
8vtembna4
/* ,LP^v'[V7
**Utility.java \Rb:t}
*/ ^do6?e`?-
package NetFox; pw5{=bD
k2tSgJW
Od^Sr4C
public class Utility { -Sn'${2
LAY:R{vI
X;2LK!x;y
public Utility() fms(_Q:R?
{ QleVW
ly35n`
aC%Q.+-t
} Jgg<u#
l5~O}`gfh
//线程睡眠 mlCg&fnDB
public static void sleep(int nSecond) 1e7I2g
{ ekU%^R<
try{ (9kR'kr
Thread.sleep(nSecond); 3Pgokj
} >\3\&[#"
catch(Exception e) Ok|Dh;1_
{ VIN0kRQ#
e.printStackTrace (); bar=^V)
} 8ZqLGa]
} 3Zl:rYD?
I8`$a
//日志 n\V7^N
public static void log(String sMsg) /nuz_y\J
{ ,hT.Ok={36
System.err.println(sMsg); k`A39ln7wu
} -%gEND-AP
eO(U):C2
f$n5$hJlQ
public static void log(int sMsg) Pqw<nyC.
{ ^6R(K'E}
System.err.println(sMsg); U*E)y7MY
} \G7F/$g
} =6O*AJ
-ucgET`
>T c\~l
/* s;=C&N5g
**TestMethod.java -u4")V>
*/ +4Pes
package NetFox; {7c'%e
#^Pab^Y3r-
EpyMc+.Ze'
public class TestMethod { mo] l_'
s,8zj<dUv
tl\<:8pI"
public TestMethod() ah_>:x
{ ///xx/weblogic60b2_win.exe m4m|?
try{ %>_6&A{K,d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h.F=Fhx/1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k4hk* 0Jq
SiteFileFetch fileFetch = new SiteFileFetch(bean); +xU({/
fileFetch.start(); l"1D'Hk
} Ox&G [
catch(Exception e){e.printStackTrace ();} D>@NYqMF
5oSp/M
FKu8R%9xn%
} ed}#S~4q
Y&8,f|{R
VN`fZ5*d~
public static void main(String[] args) rQ_@q_B.
{ 8.8t$
new TestMethod(); # Q,EL73;
} X<Z(,B
} 3X11Gl
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