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)); j :$Ruy
} 4!k0
for(int i=0;i<nEndPos.length-1;i++) li7"{+ct
{ L7rH=gZ&!]
nEndPos = nStartPos[i+1]; l =Is-N`
} ZtofDp5B
nEndPos[nEndPos.length-1] = nFileLength; D%%@+3a
} D]StDOmM
} "t!_bma
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!bGMVw6_
//启动子线程 __OH gp 1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *< ?~
for(int i=0;i<nStartPos.length;i++) y|Vwy4tK9
{ PC55A1(T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =`W#R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =f\BAi
nStartPos,nEndPos,i); lVra&5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p/WE[8U
fileSplitterFetch.start(); N*NGC!p`N
} yZyB.wT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oH>G3n|U^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _p^&]eQ+k#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", agUdPl$e\
nEndPos = " + nFileLength); .jK,6't^
// fileSplitterFetch[nPos.length-1].start(); %SKJ#b
og)f?4
U3OXO1
//等待子线程结束 L[aA4`
//int count = 0; E~K5n2CI
//是否结束while循环 f C_H0h3
boolean breakWhile = false; H5X.CcI&}
r t\eze_5A
"IuPg=|#
while(!bStop) 8d|#W
{ +txHj(Y`
write_nPos(); U%u%_{-
Utility.sleep(500); Fsi;[be$A
breakWhile = true; D wtvtglqV
q2}6lf,J K
[Zj6v a
for(int i=0;i<nStartPos.length;i++) ^nGKuW7\
{ Z.E@aml\
if(!fileSplitterFetch.bDownOver) =?oYEO7
{ 3`U^sr:[%
breakWhile = false; }]!?t~5*
break; :vo#(
} kB3@;z:
} O&@pi-=o
if(breakWhile) ay`A Gr
break; .0b4"0~T6
? e<D +
rcU*6`IWA
//count++; ''3b[<
//if(count>4) dk[MT'DV
// siteStop(); aYrbB#
} 6)j/"9oY
qfS ]vc_N
;tG@ 6
System.err.println("文件下载结束！"); I6lWB(H!u
} n1r'Y;G
catch(Exception e){e.printStackTrace ();} R!y`p:O C
} ka?EXF:
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u.9syr
//获得文件长度 "*JyNwf
public long getFileSize() i=AQ1X\s
{ a*bAf'=
int nFileLength = -1; Su*f`~G];
try{ 6!$2nK+
URL url = new URL(siteInfoBean.getSSiteURL()); >NMq^J'/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gm.2!F=R4A
httpConnection.setRequestProperty("User-Agent","NetFox"); }y&tF'qG
4B$|UG
!63]t?QXMG
int responseCode=httpConnection.getResponseCode(); bW?cb5C
if(responseCode>=400) &E0L 2gbI
{ Q1^kU0M}
processErrorCode(responseCode); v)s; wD
return -2; //-2 represent access is error Gzkvj:(V
} cTu"Tu\Qw
wNQhg
*EllE+M{n
String sHeader; r31)Ed$
~tB#Q6`nB
~d"9?K^#
for(int i=1;;i++) kmur={IR
{ @;`d\lQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "U o~fJ
//Utility.log(in.readLine()); BVe c
sHeader=httpConnection.getHeaderFieldKey(i); Pt\GVWi_t
if(sHeader!=null) HMl M!Xk?
{ H}PZJf_E
if(sHeader.equals("Content-Length")) lqZUU92;
{ FfpP<(4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eiJ~1HX)
break; {jOV8SVL
} GFfZ TA
} 3fd?xhWbN
else 7;3;8Q FX
break; $9rQ w1#e
} D]NJ^.X
} k4+Q$3"
catch(IOException e){e.printStackTrace ();} Ux+UcBKm-
catch(Exception e){e.printStackTrace ();} 9`T2
qLa6c2o,
Bh5z4
Utility.log(nFileLength); 2f0qfF
HJ0Rcw%
(Q F-=o
return nFileLength; A#Ne07d
} ?4H>1Wkb
JN>h:
h)pYV>!d
//保存下载信息（文件指针位置） qt`HP3J&
private void write_nPos() |<!xD iB
{ iCNJ%AZH
try{ I~)A!vp
output = new DataOutputStream(new FileOutputStream(tmpFile)); n#"N"6s
output.writeInt(nStartPos.length); PsO>&Te2
for(int i=0;i<nStartPos.length;i++) fX{Xw0
{ e_3($pj
// output.writeLong(nPos); 5#BM
output.writeLong(fileSplitterFetch.nStartPos); Zr|z!S?aSC
output.writeLong(fileSplitterFetch.nEndPos); &h'NC%"v
} M~Ph/
output.close(); 5nS}h76mZ
} H{I,m-
catch(IOException e){e.printStackTrace ();} Y[.f`Ei2
catch(Exception e){e.printStackTrace ();} o|Kd\<rY
} bA02)?L
\%Lj !\
@YHt[>*S
//读取保存的下载信息（文件指针位置） DsCbMs=Y
private void read_nPos() Mt\.?V:
{ `9mc+
try{ 3_N1y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k~IRds@G
int nCount = input.readInt(); }dpE>
nStartPos = new long[nCount]; 0s.X
nEndPos = new long[nCount]; 1BOv|xPjZ
for(int i=0;i<nStartPos.length;i++) EFzPt?l
{ 8)XAdAr
nStartPos = input.readLong(); ,)PpE&
nEndPos = input.readLong(); ;uN&yj<}a
} Zy=DY
input.close(); ]/{iIS_
} V@pUU~6R
catch(IOException e){e.printStackTrace ();} 0 LQ%tn
catch(Exception e){e.printStackTrace ();} CS\8ej}y
} )*nZ6Cg'
{-1N@*K
'H-hp
private void processErrorCode(int nErrorCode) YYF.0G}
{ 0S&C[I o6
System.err.println("Error Code : " + nErrorCode); K96N{"{iI%
} _3zJ.%
Iwe
i0'g$
//停止文件下载 F!zGk(Pu
public void siteStop() =k##*%
{ {Lugdf'
bStop = true; ?eDZ-u9)
for(int i=0;i<nStartPos.length;i++) &EJ/Rl
fileSplitterFetch.splitterStop(); 79Ur1-]/
vf?Xt
GsU.Lkf
} bwe)_<c
} 9v?rNJs
//负责部分文件的抓取 =+w/t9I[
**FileSplitterFetch.java "1%\Fil
*/ JQ9+kZ
package NetFox; .$a|&P=S
'RZ0,SK'
cS(=wC
import java.io.*; ?D['>Rzu
import java.net.*; @nOuFX4
2[i(XG{/
(&Mv!6]
public class FileSplitterFetch extends Thread { K)GpQ|4:<
?^WX]SAl
5V8`-yO9
String sURL; //File URL cp2a @
long nStartPos; //File Snippet Start Position *0x!C8*`Xe
long nEndPos; //File Snippet End Position =55V<VI
int nThreadID; //Thread's ID 2hY"bpGW
boolean bDownOver = false; //Downing is over k_`YVsEYP
boolean bStop = false; //Stop identical lw_@(E]E
FileAccessI fileAccessI = null; //File Access interface aj]pN,g@N
KN'twPFq
\0.!al0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 't+'rG6x
{ =Y*zF>#lP
this.sURL = sURL; 5h6-aQU[
this.nStartPos = nStart; T[kS;-x
this.nEndPos = nEnd; &"DD&87N%
nThreadID = id; {Zo*FZcaX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g=jB'h?
} '#lc?Y(pJ2
pER[^LH_)
MUUhg
public void run() ?N]G;%3/
{ W/.Wp|C}K3
while(nStartPos < nEndPos && !bStop) 2/ejU,S
{ |y&vMx~t
y\Wp}}
.t.4y. 97
try{ ='6@^6y
URL url = new URL(sURL); p~OX1RBI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?dmwz4k0
httpConnection.setRequestProperty("User-Agent","NetFox"); n^` `)"
String sProperty = "bytes="+nStartPos+"-"; #rQT)n
httpConnection.setRequestProperty("RANGE",sProperty); \jr-^n]
Utility.log(sProperty); #g~]2x
zz #IY'dwT
&?# YjU"
InputStream input = httpConnection.getInputStream(); #>2cfZ`6'J
//logResponseHead(httpConnection); JPpNCC.b
\`W8#fob
j43i:c;F
byte[] b = new byte[1024]; rh T!8dTk
int nRead; 74a k|(!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) * yGlX[
{ WnhH]WY
nStartPos += fileAccessI.write(b,0,nRead); RmQ>.?
//if(nThreadID == 1) 2=$ F*B>9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )h1 `?q:5
} (zw.?ADPCT
rBZ00}
vy5I#q(k
Utility.log("Thread " + nThreadID + " is over!"); g{JH5IZ~
bDownOver = true; [6)vD@
//nPos = fileAccessI.write (b,0,nRead); V o%GO9b;
} = Q"(9[Az
catch(Exception e){e.printStackTrace ();} O^IS:\JX&
} 3 <Zo{;
} -Fc 9mv(H
D0yH2[j+
rd^j<
//打印回应的头信息 gF\ac%9
public void logResponseHead(HttpURLConnection con) m Gx{Vpt
{ 4MRN{W6
for(int i=1;;i++) 0OBwe6*
{ RQ,X0pS
String header=con.getHeaderFieldKey(i); qWJap-hb
if(header!=null) {'cdi`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :<uCi\9(
Utility.log(header+" : "+con.getHeaderField(header)); LG'1^W{a
else :|Bzbn=N2
break; t![972.&
} 1pT/`x
} BRtT 7
xLw[ aYy4
eNrwkV^
public void splitterStop() c+jnQM'
{ i}>}%l|
bStop = true; D!D}mPi[
} 1~[GGl
~e=KBYDBu
S9 @*g3
} 5K00z?kD2V
M] W5%3do
'8b=4mrbH
/* _#w5hXcu
**FileAccess.java a]4|XJ_
*//文件访问(定位，写) j2jUrl
package NetFox; uKo4nXVtp
import java.io.*; mWuhXY^Q
D1EHT}
U!T#'H5'-
public class FileAccessI implements Serializable{ m^4Ojik
Ps~)l#gue
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kv`5"pa7M
RandomAccessFile oSavedFile; +'UxO'v3]
long nPos; t_Ul;HVPS
+Q!Kj7EU/
(ewcj\l4*
public FileAccessI() throws IOException IXsOTBM
{ 8\[qR_LV
this("",0); _RX*Ps=
} D66!C{
jxnb<!|?H@
tfjbG;R
public FileAccessI(String sName,long nPos) throws IOException /P*ph0S-
{ #M92=IH
oSavedFile = new RandomAccessFile(sName,"rw"); D$SO 6X~
this.nPos = nPos; 7/BA!V(na
oSavedFile.seek(nPos); DIh[%
} -3C$br
F-Ywl)
CxVrnb[`q
public synchronized int write(byte[] b,int nStart,int nLen) g'V,K\TG
{ EZ^M?awB4
int n = -1; 4'XCO+i#
try{ &XSe&1
oSavedFile.write(b,nStart,nLen); 0*o=JM]
n = nLen; 'Y5=A!*@tf
} 62#8c~dL
catch(IOException e) =4Wjb
{ k?=_p6>
e.printStackTrace (); G_?qY#"(
} 'deqF|Iox
cS"PIelR
{1W,-%
return n; %$F\o1S
} sUsIu,1Q
V_pKe~
5@~5RNrq2
} LU@+O12
R= *vPS
m`/!7wQs
/* [ ]=}0l<J
**SiteInfoBean.java U&y?3
*/ 8wA'a'V.
package NetFox; sg,9{R ^
/ee4 v!
5VW*h
public class SiteInfoBean { cin3)lm
CB?,[#r5f
,T7(!)dR
private String sSiteURL; //Site's URL L!kbDbqn
private String sFilePath; //Saved File's Path mKBPIQ+ZS
private String sFileName; //Saved File's Name 1PT0<C-
private int nSplitter; //Count of Splited Downloading File kam\dn04
on0>_-n)
Y ptP_R:2p
public SiteInfoBean() Z6oA>D
{//nSplitter的缺省值为5 "_e/O&-cH
//default value of nSplitter is 5 GZ/vUe
this("","","",5); ?:sQ]S/Er
} ^ZO3:"t!w
`Yc>I!iN
X !l#1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4gK_'b6"
{ +jX.::UPm
sSiteURL= sURL; l%$co07cX
sFilePath = sPath; (Y]G6> Oa
sFileName = sName; PQ[x A*
this.nSplitter = nSpiltter; GG[$-
MM4Eq>F/
Hf$LWPL)lM
} KmRxbf
STgYXA(
QsH Fk5)
public String getSSiteURL() JD$;6Jv3P
{ W=T,hOyh<W
return sSiteURL; HCKj8-*
} Oe}6jcb6&
bn<}
{V~Gr
public void setSSiteURL(String value) 5R7DD5c[
{ $qj||zA
sSiteURL = value; Md,KW#
} *>p#/'_E
#:3~I
Ie8jBf -
public String getSFilePath() fQOh%i9n5
{ :i:M7}r
return sFilePath; 4PAuEM/z
} >D/+04w
6,;7iA]
xBi``x2eY
public void setSFilePath(String value) :0RfA%
{ U49 `!~b7
sFilePath = value; +cnBEv~y
} 4I^8f||b_
VCUEzR0
sj0{;>>%+N
public String getSFileName() 'w5g s}1D
{ p8Wik<'^
return sFileName; MUd 9R
} _-/<bO
vL"[7'
fbK`A?5K
public void setSFileName(String value) LdM9k(
{ F[5\ x0
sFileName = value; gT~Yn~~b
} ;nB.f.e`
@fxDe[J:
@Iy&Qo
public int getNSplitter() )~l`%+
{ @-QDp`QtI
return nSplitter; y6S:[Z{~A
} VaRP+J}UA.
N/&t)7
41V}6+$g
public void setNSplitter(int nCount) +Qe&#"O0
{ '+cPx\4
nSplitter = nCount; :F`yAB3
} -<tfbaA
} N^{+1u7
d]6#pSE
U}Aoz|
/* J_PbRb
**Utility.java b)Px
*/ 60 z =bd]
package NetFox; <c&6M
/ !*+9+h
)2jBhT
public class Utility { 9c_h+XN?y
1v^eXvY
\E<t'\>@X
public Utility() [10;Mg
{ UI>?"b6 L
ZBAtRs
3bW(VvgcL4
} x#{.mN
R2[-Q"|Ra
//线程睡眠 z3:tSjF
public static void sleep(int nSecond) e):rr*
{ B:Xmc,|,
try{ M'4$z^@Z
Thread.sleep(nSecond); %!i|"FNc
} EecV%E
catch(Exception e) C{8d^SCA"
{ }QqmDK.
e.printStackTrace (); `fRp9o/
} oG_-a(N
} xiW;Y{kZ
41[1_p(
//日志 xrPC
public static void log(String sMsg) qg+bh
{ p7pJ90~E
System.err.println(sMsg); Y@Zv52,
} cKKl\g@}
lp;=f
D!oELZ3
public static void log(int sMsg) #,KjJ
{ 71# ipZ
System.err.println(sMsg); Cd"iaiTD0
} f2y:K6$'l*
} xC,;IS k,
d;$<K
<+oTYPgD9
/* e5 ?;{H
**TestMethod.java TEK]$%2
*/ eaxp(VX?oy
package NetFox; [*k25N
Iw<: k
+W6QtB6
public class TestMethod { ]EhW
VkNg Vjg
W_E0+
public TestMethod() [0(+E2/:2
{ ///xx/weblogic60b2_win.exe a\Ond#1p
try{ d}.*hgk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c9eLNVM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kq SpZoV0'
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2C!Ko"1Y'
fileFetch.start(); )lo;y~ o
} 2V1|b`b#4
catch(Exception e){e.printStackTrace ();} }op0`-Xb
}? W[D
8a^E{x@HT
} ,/=Fm
Nx8~Rn
~P47:IZf
public static void main(String[] args) i@C1}o-/
{ Q3$AL@".
new TestMethod(); ;ss,x
} uq>\pO&P
} ]d}U68$T+
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