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)); =CBY_
} MZJ@qIg[Y
for(int i=0;i<nEndPos.length-1;i++) v_U+wga
{ TS2zzYE6Z
nEndPos = nStartPos[i+1]; ;iA6[uz
} ]#$l"ss,
nEndPos[nEndPos.length-1] = nFileLength; bhk:Szqz
} d\eTyN'rA
} CuT~ Bj
~9Xs=S!
+95: O 8
//启动子线程 c+dmA(JC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z+p'3
for(int i=0;i<nStartPos.length;i++) {Xr|L
{ LVHIQ9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q[rmsk2L'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =74yhPAW
nStartPos,nEndPos,i); V LXU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZMp5d4y5
fileSplitterFetch.start(); g>gVO@"b2
} Y8i'=Po%,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9Rf})$o+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _P].Z8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P5?M"j0/^
nEndPos = " + nFileLength); B}?$kp
// fileSplitterFetch[nPos.length-1].start(); e-&0f);i
|.]g&m)y^h
&];:uYmMU
//等待子线程结束 Fu%D2%V$/
//int count = 0; i!yu%>:M
//是否结束while循环 VbU*&{j
boolean breakWhile = false; 3'*}ZDC
$M:Ru@Du2
!tuN_
while(!bStop) rlRRGJ\l
{ au+6ookT
write_nPos(); K^6fg,&
Utility.sleep(500); r &.gOC
breakWhile = true; xZE%Gf_U
aG*Mj;J
Uo]x6j<
for(int i=0;i<nStartPos.length;i++) dj}y6V&
{ oS0rP'V^
if(!fileSplitterFetch.bDownOver) _6Z}_SiOl
{ 0?80V'
breakWhile = false; ;NoD4*
break; fkHCfcU
} -a+oQP]O
} R?Ys%~5
if(breakWhile) jhx@6[
break; W{!Slf
gH u!~l
b<E0|VW
//count++; 9JtPP
//if(count>4) (~U1X4
// siteStop(); KlbUs\E
} _N1UL?
#cCR\$-~
<jz\U7TBf
System.err.println("文件下载结束！"); ?S2!'L
} M/x*d4b_
catch(Exception e){e.printStackTrace ();} QnMN8Q9
} 8GKqPS+
du5|/
[j;#w,Wb
//获得文件长度 7dh--.i
public long getFileSize() "k>;K,:
{ X/AA8QV o
int nFileLength = -1; $T2n^yz
try{ `21$e
URL url = new URL(siteInfoBean.getSSiteURL()); r1]DkX <6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j0(+Kq:J
httpConnection.setRequestProperty("User-Agent","NetFox"); x6iT"\MO
^v+7IFn
*Q`y'6S
int responseCode=httpConnection.getResponseCode(); wK*b2r}0/
if(responseCode>=400) 0(h'ZV
{ egHvI&w"o
processErrorCode(responseCode); ^2<nn op
return -2; //-2 represent access is error R![)B97^
} \!J9|
] RLEyDB
_[p@V_my
String sHeader; 69C>oX
-Izc-W
Xhk_h2F[
for(int i=1;;i++) nNP{>\x;"
{ #- z(]Y,y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;e#bl1%#
//Utility.log(in.readLine()); %:=Jr#a
sHeader=httpConnection.getHeaderFieldKey(i); S!{Kn ;@
if(sHeader!=null) tLc~]G*\`s
{ 2nv-/%]
if(sHeader.equals("Content-Length")) #Py\'
{ Ynx.$$`$=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;sZHE&+
break; mEVne.D
} Q"D%xY
} bqI| wGCA"
else ?YA5g' l
break; PTf.(B"z
} 1}DUe.a
} d_!lRQ^N
catch(IOException e){e.printStackTrace ();} <f/wWu}
catch(Exception e){e.printStackTrace ();} n%%u0a%
c ;@k\6
YA'_Ba(v)
Utility.log(nFileLength); jb {5
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return nFileLength; S/)J<?<b
} *s}j:fJ
r<XlIi
H>Ws)aCq
//保存下载信息（文件指针位置） lk. ;
private void write_nPos() 3!<} -sW4
{ B_uAa5'
try{ oHj64fE9
output = new DataOutputStream(new FileOutputStream(tmpFile)); d*(wU>J '
output.writeInt(nStartPos.length); %n<.)R
for(int i=0;i<nStartPos.length;i++) W*D].|
{ ypA)G/;
// output.writeLong(nPos); OK1f Y`$z
output.writeLong(fileSplitterFetch.nStartPos); n?z^"vv$i
output.writeLong(fileSplitterFetch.nEndPos); iT}L9\
} ;x~[om21;
output.close(); _0c$SK
} ,Z1W3;O
catch(IOException e){e.printStackTrace ();} Q{))+'s2h
catch(Exception e){e.printStackTrace ();} 'h~I#S4!
} J"W+9sI0
J`@#yHL
q oJ4w7
//读取保存的下载信息（文件指针位置） G?&T0
private void read_nPos() e)x;3r"j
{ jpW(w($XL
try{ M!E#T-)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |Je+y;P7
int nCount = input.readInt(); M_monj}Z
nStartPos = new long[nCount]; },'Ij; %%Q
nEndPos = new long[nCount]; sxBRg=
for(int i=0;i<nStartPos.length;i++) !YJ^BI
{ /qalj\ud
nStartPos = input.readLong(); nM,5KHU4a
nEndPos = input.readLong(); -ipfGb
} TPeBb8v8D
input.close(); {cF>,T
} `9yR,Xk=l
catch(IOException e){e.printStackTrace ();} Z<t(h=?
catch(Exception e){e.printStackTrace ();} fqgm`4>
} %M_5C4&6
B,dHhwO*l
+iL,8eW
private void processErrorCode(int nErrorCode) 05>xQx?"m4
{ FII>6c
System.err.println("Error Code : " + nErrorCode); gc6T`O-_;
} 0XNj!^&
T2$V5RyX
Fo1|O&>
//停止文件下载 mlmXFEC
public void siteStop() 1n86Mp1.e
{ $EuWQq7OI2
bStop = true; Gr a(DGX
for(int i=0;i<nStartPos.length;i++) VSI.c`=,
fileSplitterFetch.splitterStop(); yt-F2Z&
nPj/C7j
LpJ_HU7@lk
} $*u{i4b
} <Gr775"
//负责部分文件的抓取 dGb]`*E
**FileSplitterFetch.java c*"TmDY
*/ s3LR6Z7;i
package NetFox; 43?J~}<Vs
+J~q:b.
yfD)|lK
import java.io.*; G2x5%`
import java.net.*; 6c/Tm0[
A-dL_3
7v~\c%1V
public class FileSplitterFetch extends Thread { F ;m1I+;
Jc#()4
%Jr6pmc
String sURL; //File URL 2 #+g4
long nStartPos; //File Snippet Start Position VK)K#!O8
long nEndPos; //File Snippet End Position 5_mb+A n,
int nThreadID; //Thread's ID #^bkM)pc
boolean bDownOver = false; //Downing is over [@qUQ,Ie
boolean bStop = false; //Stop identical Yjr6/&ML
FileAccessI fileAccessI = null; //File Access interface W,^(FR.
:_qgpE<
>Tm|}\qEb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U*' YGv
{ L|3wGY9E
this.sURL = sURL; h4GR:`
this.nStartPos = nStart; 2Q,8@2w;
this.nEndPos = nEnd; mYudUn4Wo
nThreadID = id; k_=~ObA$g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `aS9o]t
} g]g2`ab |
"5-S:+
hOX$|0i
public void run() Cz\(.MWNZ
{ USnKj_e
while(nStartPos < nEndPos && !bStop) @ P=eu3
{ ezt_ct/Z
#@m*yJg<
$rySz7NI
try{ ^;2dZgJ4^
URL url = new URL(sURL); lxRzyx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FRicHs n
httpConnection.setRequestProperty("User-Agent","NetFox"); ,T{(t@
String sProperty = "bytes="+nStartPos+"-"; pPm9v_G
httpConnection.setRequestProperty("RANGE",sProperty); [G/q*a:K
Utility.log(sProperty); H]. 4~ 8
Hy<4q^3$G
><X!~by
InputStream input = httpConnection.getInputStream(); 3:rH1vG.m
//logResponseHead(httpConnection); >a]4}
1:%m >4U
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byte[] b = new byte[1024]; 6dh@DG*k
int nRead; }0#cdw#gH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cz/mUU
{ v UAYYe
nStartPos += fileAccessI.write(b,0,nRead); lHpo/R:
//if(nThreadID == 1) vpY|S2w)Bp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :\*hAV1i
} [FKmZzEy
tIb?23K0
T[=XGAJ
Utility.log("Thread " + nThreadID + " is over!"); XbJ=lH
bDownOver = true; eBTy!!
//nPos = fileAccessI.write (b,0,nRead); &50Kn[
} s &v<5W2P
catch(Exception e){e.printStackTrace ();} >qn@E?Uf
} G{rUqo
} v&U'%1|
$2F*p#l(<Z
:&dY1.<N+
//打印回应的头信息 /|y3M/;F
public void logResponseHead(HttpURLConnection con) x#e(&OjN7
{ b9(d@2MtK
for(int i=1;;i++) Y#c11q Z
{ L_jwM^8
String header=con.getHeaderFieldKey(i); _Bh-*l?K>
if(header!=null) '?Q [.{<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !&C8y
Utility.log(header+" : "+con.getHeaderField(header)); Y}"|J ~
else R,A|"Q
break; Yuze9b\[
} 0x0.[1mB
} ..7"&-?g{4
<W vuW6
3vOI=ar=L~
public void splitterStop() {R[lsdH(X
{ pM\)f
bStop = true; B4&@PX"'>,
} IgC)YIhd
V0L^pDLOV
"8Pxf=
} SV]M]CAe
3l>P>[<o
IqEY.2KN
/* L]#J?lE&
**FileAccess.java 2?ZHWS>U
*//文件访问(定位，写) lw? f2_fi
package NetFox; )xP]rOT
import java.io.*; ~@z5Ld3xz
;4F[*VF!w
S'Q$N-Dy
public class FileAccessI implements Serializable{ XFmnZpqXH
[j}%&$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \XMl8G
RandomAccessFile oSavedFile; [_qBp:_j?s
long nPos; I~"-
Yq/|zTe{
M.d{:&@`%
public FileAccessI() throws IOException 622mNY
{ Q-}oe Q
this("",0); U*k$pp6\b~
} X!,Ngmw.
-H.;73Kb[
+U+c]Xgt
public FileAccessI(String sName,long nPos) throws IOException 'y}A3RqN
{ Ff& VBm
oSavedFile = new RandomAccessFile(sName,"rw"); \{G6!dV|S
this.nPos = nPos; SNff
oSavedFile.seek(nPos); Y!o@"Ct
} 1WcT>_$
u bP2ws
vD1jxk'fd
public synchronized int write(byte[] b,int nStart,int nLen) BD=;4SLT
{ DfV_08
int n = -1; IwFg1\>
try{ K(6=)
oSavedFile.write(b,nStart,nLen); \s<iM2]Kl
n = nLen; %)l2dK&9"j
} wC=IN
catch(IOException e) |ki#MtCp
{ gNLjk4H,S[
e.printStackTrace (); Ks X@e)8u
} V%ykHo
LAf!y"A#
orzdq
return n; kf-ZE$S4
} N4fuV?E`
3QUe:8
K]kL?-A#'
} W .Hv2r3
*TE6p
,{8~TVO
/* 9KXp0Q?-$
**SiteInfoBean.java r7ywK9UL
*/ C _[jQTr
package NetFox; Q1&: +7%
Q:-H UbB
>PySd"u
public class SiteInfoBean { s o~p+]
^5,ASU
-+Q,xxu
private String sSiteURL; //Site's URL 3O#7OL68v
private String sFilePath; //Saved File's Path [mWo&Ph[-
private String sFileName; //Saved File's Name R"O9~s6N
private int nSplitter; //Count of Splited Downloading File kmov(V
yg\A&0I
O%c6vp7
public SiteInfoBean() tinN$o Xy
{//nSplitter的缺省值为5 wM!QU{Lz
//default value of nSplitter is 5 A|Y\Y}
this("","","",5); YLobBtXc9
} Sk;IAp#X9
msY"Y*4
k92X)/ll'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %WCpn<)
{ |UR.7rOV
sSiteURL= sURL; `GPK$ue
sFilePath = sPath; TF=S \ Q
sFileName = sName; e@8I%%V,
this.nSplitter = nSpiltter; RE"}+D
gscsB4<
tanuP@O
} y[r T5ed
9=< Z>
'R=o,=
public String getSSiteURL() I}k!i+Yl
{ dc?Yk3(Y
return sSiteURL; &# @1n
} oY.JK
N(1jm F
&G<ZK9Ot}0
public void setSSiteURL(String value) `RmB{qgB
{ 9w0 ^=
sSiteURL = value; n:<avl@o<
} y/i"o-}}~|
lsio\ $
8sbS7*#
public String getSFilePath() 4El{2cfA
{ f"-<Z_
return sFilePath; UNY>Q7
} mLq?-&F
sgB3i`_M
j6v +S
public void setSFilePath(String value) Rf%ver
{ Xq)'p8C?
sFilePath = value; >nr1|2
} s#qq% @
:'!?dszS
9d2$F9]:o
public String getSFileName() R9#Z=f,
{ 8g0& (9<)
return sFileName; 5/*ZqrJw{"
} 1m![;Pg3
'GW@P
Hss{Sb(
public void setSFileName(String value) %%k[TO
{ "+XO[WGc
sFileName = value; c"QH-sE
} *i$+i
^WD[>E~
=3J~Fk
public int getNSplitter() u YH{4%
{ $x2<D :
return nSplitter; qrOTb9&y
} c|O5Vp}
-#Wc@\;
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public void setNSplitter(int nCount) h2BD?y
{ bpU^|r^W
nSplitter = nCount; _D+7w'8h
} fi,=z
} 94lmsE
P4N{lQ.>
hnY^Z_v!
/* (8EZ,V:
**Utility.java cdGl[dQ/
*/ 74[}AA
package NetFox; a\MU5%}\
OVivJx
bC@b9opD
public class Utility { |w>DZG!}1-
<]!IC]+
ev@1+7(
public Utility() (h%wO
{ i$NnHj|
4Fz^[L}[
.[_&>@bmrP
} $YSOkyC?
?=T&|pp
//线程睡眠 j1d=$'a "
public static void sleep(int nSecond) )1i)I?m
{ <w:fR|O
try{ C<7J5
Thread.sleep(nSecond); LvAIAknc
} k1cBMDSokO
catch(Exception e) #/1Bam6
{ [ z&y]~
e.printStackTrace (); kO9yei
} U{_O=S u
} WW_X:N~~e\
c,-< 4e
//日志 -+4$W{OK*0
public static void log(String sMsg) +X- k)9
{ ![V<vIy
System.err.println(sMsg); J{1O\i
} i&KbzOY
|Y99s)2&N
EfUo<E
public static void log(int sMsg) \e?T9c6,
{ &\(YmY
System.err.println(sMsg); o^NQ]BdH8
} {C6Yr9
} Y}[r`}={
JBg>E3*N
3&zmy'b*:
/* R.fRQ>rI
**TestMethod.java . =+7H`A
*/ t+#Ss v8
package NetFox; vTP_vsdeG
8q0 .yhb
Gmc"3L
public class TestMethod { VEn%_9(]
tJn2:}-s
un/R7"
public TestMethod() ~cez+VQe
{ ///xx/weblogic60b2_win.exe _1hqD EM
try{ +Rvj]vd}&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9Z*vp^3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ue\&
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2V0R|YUt
fileFetch.start(); q\/|nZO4
} 9QYU J
catch(Exception e){e.printStackTrace ();} L\B+j+~
]x Kmz
YA|*$$
} %NBD^gF
;L)}blN.
5N6%N1
public static void main(String[] args) `BvcIn4do
{ n}+ DO6J
new TestMethod(); 6`s[PKP.
} r*$"]{m}
} +`4|,K7'
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