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)); 2x3'm
} CYlZ<W'
for(int i=0;i<nEndPos.length-1;i++) GMLDmTV
{ Mx& P^#B3
nEndPos = nStartPos[i+1]; pC9Ed9uRK
} -8F~Tffx
nEndPos[nEndPos.length-1] = nFileLength; }*0OLUFFJ
} L_$M9G|5n
} sA6Ku(9
\g|u|Y.2[
Q)pm3Wi
//启动子线程 K.CwtUt`54
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #)im9LLC#
for(int i=0;i<nStartPos.length;i++) 6OeRBD&
{ .^]=h#[e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >C|/%$kk:f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OW$? 6
nStartPos,nEndPos,i); "f'pa&oHi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t%jB[w&,os
fileSplitterFetch.start(); N"d*pi#h
} 6fxf|R\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RJMrSz$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?R2`RvQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~4p@m>>
nEndPos = " + nFileLength); ba_T:;';0
// fileSplitterFetch[nPos.length-1].start(); ep]tio_
)2c[]d/a4
q!l[^t|;
//等待子线程结束 ==d@0`
//int count = 0; G[U'-a}I
//是否结束while循环 Vj.5b0/(
boolean breakWhile = false; O{" A3f
((BuBu>
d9/YW#tm
while(!bStop) Y)%CxaO`
{ !Pmv
write_nPos(); )KvQaC
Utility.sleep(500); m*VM1kV
breakWhile = true; 1EW-%GQO
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3e)3t`
for(int i=0;i<nStartPos.length;i++) lW F=bz0
{ gHS;RF9
if(!fileSplitterFetch.bDownOver) E&G_7->
{ 5x/q\p-{/
breakWhile = false; m<ZwbD
break; nLZT3`@~,
} nU Oy-c
} eit>4xMu
if(breakWhile) ebF},Q(48
break; k]*DuVCOX
$~,]F
qwka77nNT
//count++; H^s@qh)L
//if(count>4) >j]*=&,7
// siteStop(); #vN\]e
} )9@I7QG?
gd9ZlHo'Id
pH&Q]u;O
System.err.println("文件下载结束！"); kTQ`$V(>&
} 'ad|@Bh
catch(Exception e){e.printStackTrace ();} Jt4T)c9
} c9e }P
dOY+| P\
ye U4,Ko
//获得文件长度 )4[{+OJa
public long getFileSize() [MM11K
{ h~$Q\WCm#
int nFileLength = -1; #mqz*=L3
try{ NJ-cP m
URL url = new URL(siteInfoBean.getSSiteURL()); 7{oG4X!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SZ}t_w `
httpConnection.setRequestProperty("User-Agent","NetFox"); Mnpb".VU#T
B^(0>Da\
?5m[Qc(<
int responseCode=httpConnection.getResponseCode(); A0*u(15%
if(responseCode>=400) ]2Aqqy
{ 'Mjbvh4
processErrorCode(responseCode); Kb%j;y
return -2; //-2 represent access is error 8xUmg&
} ;8sEE?C$g
(bo{vX
hB:R8Y^?H
String sHeader; Rkfr4
8<u_ wt@
~S Js2-2
for(int i=1;;i++) 6USet`#
{ BzH7E[R49
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ih1s`CjG
//Utility.log(in.readLine()); [_j.pMH/P
sHeader=httpConnection.getHeaderFieldKey(i); FE1dr_i
if(sHeader!=null) ,2?"W8,
{ DSix(bs9
if(sHeader.equals("Content-Length")) M38,SH<
{ n15c1=gs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zx{\SU
break; Qwx}e\=
} hD\C[C,
} Cm}ZeQ
else 5}e-~-
break; lqPRUkin
} "z^Ysvw&~
} NW=j>7
catch(IOException e){e.printStackTrace ();} LJZEM;;}
catch(Exception e){e.printStackTrace ();} {Z;W|w1t
\`x'r$CV
cd}TDd(H%
Utility.log(nFileLength); V]}/e!XK\
?"AcK"v
a(Z" }m
return nFileLength; ;BoeE3* 6
} e,I-u'mLQs
xPqpNs-,
Z<y+D-/
//保存下载信息（文件指针位置） ?MeP<5\A
private void write_nPos() @N.W#<IG
{ zE.4e&m%Z?
try{ ]8YHA}P
output = new DataOutputStream(new FileOutputStream(tmpFile)); #.}Su+XF
output.writeInt(nStartPos.length); R|t.wawCo
for(int i=0;i<nStartPos.length;i++) 5n.4>yOY
{ c#9 zw[y-L
// output.writeLong(nPos); ^f!d8 V
output.writeLong(fileSplitterFetch.nStartPos); &nPv%P,e
output.writeLong(fileSplitterFetch.nEndPos); =KT7ZSTV
} r3Z-mJ$:
output.close(); :[(X!eP
} z[qM2
catch(IOException e){e.printStackTrace ();} hFa\x5I5
catch(Exception e){e.printStackTrace ();} CNcH)2Mk
} 0e8)*2S
& A9psc(,&
_F^|n}Qbj
//读取保存的下载信息（文件指针位置） OY~5o&Oa
private void read_nPos() ?vf{v
{ WP^%[?S2
try{ )X\3bPDJR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wSV[nK
int nCount = input.readInt(); _* 4 <
nStartPos = new long[nCount]; X?rJO~5
nEndPos = new long[nCount]; XrSqUD
for(int i=0;i<nStartPos.length;i++) lW&glU(
{ pfAp2"
nStartPos = input.readLong(); ~`tc|Zu
nEndPos = input.readLong(); >1s:F5u"
} -lSm:O@'
input.close(); 9'//_ A,
} ZWf{!L,@Z
catch(IOException e){e.printStackTrace ();} .(9IAAwKn
catch(Exception e){e.printStackTrace ();} ~>}BDsM
} AH=6xtS-
*N'B(j/
?\\ ]u
private void processErrorCode(int nErrorCode) h"%6tpV-
{ >)N,V;j
System.err.println("Error Code : " + nErrorCode); L/nz95
} ;p\rgam
+< BAJWU
m}Tu^dy
//停止文件下载 8Yq6I>@!
public void siteStop() 1ygu>sKS&A
{ !c1 E
bStop = true; ew?UHV
for(int i=0;i<nStartPos.length;i++) S2jo@bp!
fileSplitterFetch.splitterStop(); NV9=~cx
C UBcU
]iLfe&f
} Iobo5B
} @gX@mT"
//负责部分文件的抓取 C?x
**FileSplitterFetch.java uc7np]Z
*/ jIdhmd* $z
package NetFox; ,PN>,hFL
={maCYlE.
DU1,i&(
import java.io.*; !JYDg
import java.net.*; mg >oB/,'Z
sFS_CyN!7
zP=J5qOZ8
public class FileSplitterFetch extends Thread { bk4%lYJ"
$8it&/JP,
]s,T` (&
String sURL; //File URL OgHWmb
long nStartPos; //File Snippet Start Position |Ca$>]?
long nEndPos; //File Snippet End Position {8I93]
int nThreadID; //Thread's ID Uk*s`Y
boolean bDownOver = false; //Downing is over ol`]6"Sc
boolean bStop = false; //Stop identical J)g(Nw,O
FileAccessI fileAccessI = null; //File Access interface _5y)m5I
PrN?;Z.
iQa Q"s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2? !b!
{ kFk+TXLDIt
this.sURL = sURL; O~aS&g/sf
this.nStartPos = nStart; RNvtgZ}k{X
this.nEndPos = nEnd; de ](l687I
nThreadID = id; pd X9G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OZt'ovY
} t]vX9vv+D
I/^Lr_\
?'_iqg3
public void run() m?B@VDZ
{ ?+Qbr$]
while(nStartPos < nEndPos && !bStop) (x=NA )
{ K{|;'N-1
Q_uv.\*z_
o~GhV4vq
try{ C!Tl?>Tt
URL url = new URL(sURL); s_1]&0<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^uZ%d
httpConnection.setRequestProperty("User-Agent","NetFox"); @&M$`b ^
String sProperty = "bytes="+nStartPos+"-"; hZzsZQ`
httpConnection.setRequestProperty("RANGE",sProperty); .2Rh_ful
Utility.log(sProperty); \-sDRW
$~ItT1k_
!4z"a@$
InputStream input = httpConnection.getInputStream(); Jge;/f!i
//logResponseHead(httpConnection); 4L5Wa~5\
6'wP?=
iSFgFJG^
byte[] b = new byte[1024]; r2&{R!Fj`
int nRead; 3{$cb"5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `pcjOM8u
{ 6(ja5)sn*
nStartPos += fileAccessI.write(b,0,nRead); hR{Fn L
//if(nThreadID == 1) }:hdAZ+z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u-k*[!JU
} sHEISNj/^
d0N7aacY
yr;oq(&N
Utility.log("Thread " + nThreadID + " is over!"); /D~ ,X48+
bDownOver = true; #vS>^OyP
//nPos = fileAccessI.write (b,0,nRead); 3d,|26I7f
} iWtWT1n8n
catch(Exception e){e.printStackTrace ();} E|^a7-}|
} 9'4cqR
} ]q?<fEG2<
St(7@)gvY
s}HTxY;
//打印回应的头信息 8o4 vA,
public void logResponseHead(HttpURLConnection con) 0q62{p7
{ +5T0]!
for(int i=1;;i++) 6xj&Qo
{ >)VrbPRuA
String header=con.getHeaderFieldKey(i); 2&Efqy8}DZ
if(header!=null) ~^3B(feQ]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s'K0C8'U
Utility.log(header+" : "+con.getHeaderField(header)); +"d{P,[3J
else I.( 9{
break; =RQ>q
} K):)bL(B
} 7tt&/k?Q
#D}NT*w/
rP>5OLP
public void splitterStop() ^Nc\D7( l
{ 4Q!*h8O
bStop = true; Ig9$ PP+3
} ^,`yt^^A
I=lA7}
*J%+zH
} q&P"
R a9/L
lual'~
/* G-;pMFP(?
**FileAccess.java D%BV83S
*//文件访问(定位，写) fC81(5
package NetFox; 5SK.R;mn
import java.io.*; -$mzzYH
U:IQWlC
+i K.+B
public class FileAccessI implements Serializable{ ,':?3| $c
O"{NHNG\oT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rgOB0[
RandomAccessFile oSavedFile; 2p'qp/
long nPos; <K2 )v~
fHe3 :a5+W
7ZJYT#>b
public FileAccessI() throws IOException fw-LZ][
{ Pw+cpM8<
this("",0); 7DT9\BT
} o{ U= f6
LdRLKE<'e
="XxS|Mq3
public FileAccessI(String sName,long nPos) throws IOException Q+#, VuM
{ G:A` n;E0
oSavedFile = new RandomAccessFile(sName,"rw"); uS<&$JH
this.nPos = nPos; X\flx~
oSavedFile.seek(nPos); JZai{0se
} 9v/1>rziE
m@TU2
eLl;M4d
public synchronized int write(byte[] b,int nStart,int nLen) RX#:27:
{ 8vchLl#
int n = -1; &:Raf5G-E
try{ /y NU0/
oSavedFile.write(b,nStart,nLen); 4S+P]U*jW
n = nLen; WJ/&Ag1
} HhIa=,VY
catch(IOException e) tn:tM5m
{ t*n!kXa
e.printStackTrace (); $ABW|r
} r1t TY?
c!6.D
HbV[L)zYG
return n; QCMt4`%'u
} Q?Q!D+~mND
^gD&NbP8
wl}Q|4rZ
} _d,_&7
EK[~lIXg
"-\I?k
/* .`iOWCS
**SiteInfoBean.java 2}hEBw68
*/ HjL+Wg
package NetFox; .hn"NXy
[9*+s
(LQ*U3J]_
public class SiteInfoBean { [?_^Cy
&Q 3!ty
"y#$| TMB
private String sSiteURL; //Site's URL 0(HUy`]>
private String sFilePath; //Saved File's Path 0riTav8
private String sFileName; //Saved File's Name _sx]`3/86
private int nSplitter; //Count of Splited Downloading File $Z$BF
kOeW,:&65
EtKy?]i
public SiteInfoBean() U%m,:b6V
{//nSplitter的缺省值为5 iCa#OQ
//default value of nSplitter is 5 jIg]?4bW[
this("","","",5); @2Z{en?
} }eSaF@.
CO-9-sQx
08cCrG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ioz4kG!
{ r m\]
sSiteURL= sURL; _KLKa/3
sFilePath = sPath; 8+^q9rLii
sFileName = sName; XeJn,=
this.nSplitter = nSpiltter; K#tT \
c7,p5[
Qne@Vf kA
} bRfac/:}
o4\\q66K
9J$N5
public String getSSiteURL() lE'2\kxI?
{ /*i[MB
return sSiteURL; ?s6v>#H%
} ?sk{(UN]
Y2W|b5
Ja"?Pb
public void setSSiteURL(String value) yxik`vmH
{ U]ynnw4
sSiteURL = value; }&F|u0@b
} lvY[E9I0
W2&o'(P\
6g576
public String getSFilePath() +<a-;e{
{ _<qe= hie!
return sFilePath; #~BsI/m
} whxTCIV
.J"QW~g^
DS%~'S
public void setSFilePath(String value) n 9PYZxy
{ 0*]n#+=
sFilePath = value; x+EkL3{
} Je5}Z.3m
u5;;s@{Ye4
qHaH=g%
public String getSFileName() @IhC:Yc
{ lE'3UqK
return sFileName; J}BN}|Y@2
} X6*4IE
<hvs{}TS
Ra)wlIx
public void setSFileName(String value) >J*x` a3Q
{ ct`j7[
sFileName = value; rP|~d}+I
} %D1 |0v8}
Swa0TiT(
Ql"kJ_F!br
public int getNSplitter() )0+6^[Tqq
{ 0Q?)?8_
return nSplitter; `%;Hj _X}
} KW-GVe%8f
/oOZ>B%1s
E@,m+
public void setNSplitter(int nCount) N,W ?}
{ 'HKDGQl`
nSplitter = nCount; z36wWdRa6
} GXC,p(vbE
} YLJ^R$pi
ckGmwYP9
v;soJlxF~
/* hh8Grl;
**Utility.java ]-8WM5\qJM
*/ 3{$vN).
package NetFox; }`cf3'rdk
@,Z0u2WLl6
<aztbq?
public class Utility { ls7eypKR
JTIt!E}P
V6Mt;e)C
public Utility() @`$'sU
{ 6_,JW{#"
0civXZgj
Y<L35 ?
} w=pr?jt1:
'X<4";$mU
//线程睡眠 m8@&-,T
public static void sleep(int nSecond) !iO2yp
{ @A4$k dJ2
try{ <O5WY37"q
Thread.sleep(nSecond); sSd/\Ap
} w4(L@1
catch(Exception e) nr2 Q[9~
{ _j+!Fd
e.printStackTrace (); SQ_Je+X
} Q$uv \h;
} Kci. ,I
G54J'*Z
//日志 `78Bv>[A
public static void log(String sMsg) ~)^'5^
{ ;z.L^V0
System.err.println(sMsg); oNZ_7tU
} dvZH~mF
(:aU"5M
dgL>7X=7
public static void log(int sMsg) D|)a7_
{ OvAhp&k
System.err.println(sMsg); +$|fUn{
} @/F61Ut
} K>dB{w#gS
om`T/@_,
N0H=;CIQ
/* V"m S$MN
**TestMethod.java &\1n=y
*/ #l ZK_N|1x
package NetFox; N+'j on}U
_Ao$)Gu)
P0e-v0
public class TestMethod { jMgXIK\
GlnO8cAB
yVII<ImqIH
public TestMethod() H T|DT
{ ///xx/weblogic60b2_win.exe Keozn*fzI
try{ 'C/yQvJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GL=}Vu`(*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /M_$4O;*@
SiteFileFetch fileFetch = new SiteFileFetch(bean); $c9-Q+pZ
fileFetch.start(); )rq |t9kix
} >~SS^I0
catch(Exception e){e.printStackTrace ();} r/2= nE
5?lc%,-&
7~SwNt,
} 0?<#!
z$e6T&u5B
Pg%9hejf3
public static void main(String[] args) V&w2pp0
{ 7~ PL8
new TestMethod(); 2%dL96
} &}r"Z?f)
} 27EK+$
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