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)); {DzOXTI[Y
} BeAkG_uG
for(int i=0;i<nEndPos.length-1;i++) XJ &'4h
{ $)w9EGZ
nEndPos = nStartPos[i+1]; WEgJ_dB
} &jJj6 +P\
nEndPos[nEndPos.length-1] = nFileLength; $j?zEz
} _]~`t+W'DJ
} >OP[qj
qx,>j4yw
j9FG)0
//启动子线程 iYwzdW1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <Sm@ !yx
for(int i=0;i<nStartPos.length;i++) F Xbf7G)H
{ F@</Ev
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B}n tD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Jw;Tq"&
nStartPos,nEndPos,i); WCc7 MK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7noxUGmFw
fileSplitterFetch.start(); wxy.&a]
} pY75S5h:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +6dq+8msF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y8jwfO3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >K<n~;ON|
nEndPos = " + nFileLength); a o"\L0;{
// fileSplitterFetch[nPos.length-1].start(); UVND1XV^f
Yyl(<,Yi
_ISIq3A?
//等待子线程结束 `;?`XC"m
//int count = 0; WvV!F?uqZ
//是否结束while循环 IGKF&s*;{[
boolean breakWhile = false; 8_yhV{
W dM?{; #
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while(!bStop) ^! ?wh
{ ma__LWKM,
write_nPos(); b#XY.+ *0
Utility.sleep(500); WX@a2c.'
breakWhile = true; v?\Z4Z|f
NJ6* 7Cd
Ct-^-XD
for(int i=0;i<nStartPos.length;i++) g<ZB9;FX %
{ 5,H,OZ}
if(!fileSplitterFetch.bDownOver) JL[xrK0
{ Qq,w6ekr
breakWhile = false; kkvG=
break; [FhFeW>
} b/>L}/^PM
} J['pBlEb\
if(breakWhile) F#<$yUf%
break; 14U:.Q
P*9vs%W
Jat|n97$
//count++; /*v}.fH%
//if(count>4) ",9QqgY+
// siteStop(); M`1pze_A
} t@hE}R
X,+M?
|}hV_
System.err.println("文件下载结束！"); =\[}@Kh
} iLd_{
catch(Exception e){e.printStackTrace ();} ~hx__^]d
} mpcO-%a
g!<=NVhYt
;:2:f1_
//获得文件长度 ZA1u
public long getFileSize() ()Cw;N{E
{ v'fX'/
int nFileLength = -1; Dht,!LVb;
try{ -pb>=@Yq
URL url = new URL(siteInfoBean.getSSiteURL()); o3=2`BvJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1MVzu7
httpConnection.setRequestProperty("User-Agent","NetFox"); 3rRN~$
Y/|wOm;|
f9ziSD#
int responseCode=httpConnection.getResponseCode(); (fSpY\JPI
if(responseCode>=400) [\41
{ NG)Xk[q4
processErrorCode(responseCode); y9/x:n&]
return -2; //-2 represent access is error nqnVFkGd9
} Aw7oyC!
hXF#KVqx
cN]e{|
String sHeader; "$@Wy,yp
5(+9( \x
-FxE!K
for(int i=1;;i++) wO>P<KBU
{ ^nPk;%`0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dq.'[
//Utility.log(in.readLine()); v;=|-y
sHeader=httpConnection.getHeaderFieldKey(i); `XmT)C
if(sHeader!=null) T/9`VB%N
{ &O&;v|!9
if(sHeader.equals("Content-Length")) G]NnGL<xk
{ UoD@ix&0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b~5Q|3P9
break; {y>o6OTITR
} x JXPtm
} .66_g@1
else xD|/98
break; O|ODJOQNol
} szZ8-Y
} Ei$@)qS/
catch(IOException e){e.printStackTrace ();} 7BNu.5*y
catch(Exception e){e.printStackTrace ();} ?H30
@+iO0?f
..Dr?#Cr
Utility.log(nFileLength); 3M@!?=|U
v&#=1Zb
rzk]{W
return nFileLength; udld[f.
} JsDugn ,B
MhaoD5*9
~WKcO&
//保存下载信息（文件指针位置） 94Hs.S)
private void write_nPos() >U%:Nfo3
{ da,;IE{1u
try{ ]CL9N
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q,AM<\S
output.writeInt(nStartPos.length); jO5R0^w
for(int i=0;i<nStartPos.length;i++) `8D)j>Yh~
{ ^y1P~4w?
// output.writeLong(nPos); vwc)d{ND
output.writeLong(fileSplitterFetch.nStartPos); "i5Rh^
output.writeLong(fileSplitterFetch.nEndPos); fc,^H&
} zA<Hj;9SM
output.close(); XH"-sZt
} M8,_E\*
catch(IOException e){e.printStackTrace ();} 0r|mg::'
catch(Exception e){e.printStackTrace ();} 0/g 0=dW=
} X6Y<pw`y
n#.~XNbxv
c^%vyBMY
//读取保存的下载信息（文件指针位置） <*4'H
private void read_nPos() |cBeyqr
{ VQMPs{tm
try{ !(&N{NH9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '9w.~@7
int nCount = input.readInt(); ophQdJM
nStartPos = new long[nCount]; gPA), NrN
nEndPos = new long[nCount]; Gv$}>YJ
for(int i=0;i<nStartPos.length;i++) /8s+eHn&%
{ 3P&K<M#\
nStartPos = input.readLong(); 8'nxc#&
nEndPos = input.readLong(); G\I DgPj`
} X-mhz3Q&a
input.close(); uy t'
} /1!Wet}f
catch(IOException e){e.printStackTrace ();} d9E'4Zm
catch(Exception e){e.printStackTrace ();} U`-]U2"
} qFpRY7eq
B(z?IW&
>U2[]fu
private void processErrorCode(int nErrorCode) zHT22o56X
{ <hvVh9
System.err.println("Error Code : " + nErrorCode); r\x"nS
} 4uSC>
2rG;j52))a
InCJ4D
//停止文件下载 B0&W wa:
public void siteStop() /Ayo78Pi
{ <q dM
bStop = true; {dk%j~w8
for(int i=0;i<nStartPos.length;i++) $Qc`4x;N
fileSplitterFetch.splitterStop(); q\xT
*w/})Y3^
p^yuz (
} W :qQ
} 1(;_1@P
//负责部分文件的抓取 F^xhhz&e
**FileSplitterFetch.java ;<?mMi@<E
*/ ov@N13 ,$
package NetFox; Sj`GP p
}5I+VY7a
}qk8^W{
import java.io.*; c[n4{q1
import java.net.*; 7E}.P1
%`F&,!d
N-~Uu6zr
public class FileSplitterFetch extends Thread { 3<L>BakD
q7!$-
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String sURL; //File URL foi@z9
long nStartPos; //File Snippet Start Position "PI]k
long nEndPos; //File Snippet End Position 6(FkcC$G
int nThreadID; //Thread's ID q!sazVaDp
boolean bDownOver = false; //Downing is over =D@+_7\?
boolean bStop = false; //Stop identical SCUsDr+.
FileAccessI fileAccessI = null; //File Access interface &E(KOfk#
|hlc#t?
];n3H~2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7[)IP:I>
{ R54wNm@
this.sURL = sURL; Q9!T@
this.nStartPos = nStart; ]l~TI8gC
this.nEndPos = nEnd; S{sJX5R;
nThreadID = id; x_yQoae
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $^ wqoW%t
} "G+g(?N]j
qVpV ZH!
F"?OLV1B&
public void run() Xc!0'P0T
{ Z fQzA}QD
while(nStartPos < nEndPos && !bStop) MzWVsV
{ lebwGW,!
?df*Y5I2
@'Y^A
try{ X5V8w4NN
URL url = new URL(sURL); X:ck
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eMDO;q
httpConnection.setRequestProperty("User-Agent","NetFox"); 5ml#/kE
String sProperty = "bytes="+nStartPos+"-"; , Ac gsC
httpConnection.setRequestProperty("RANGE",sProperty); )nI}KQJ<
Utility.log(sProperty); W>*9T?
+5>*$L%8T`
1%R8q=_
InputStream input = httpConnection.getInputStream(); WLB@]JvTBY
//logResponseHead(httpConnection); *T+Bjj;w
^Qx qv
-F+ )N$CW
byte[] b = new byte[1024]; &:3uK`
int nRead; LMF@-j%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N"+o=nS
{ tcm?qro)
nStartPos += fileAccessI.write(b,0,nRead); XlPi)3m4/S
//if(nThreadID == 1) ^^O @ [_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5Wyo!pRi
} L93PDp4v
"Q>gQKgL
LxcC5/@\~(
Utility.log("Thread " + nThreadID + " is over!"); }#0i1]n$D
bDownOver = true; \m\E*c ):
//nPos = fileAccessI.write (b,0,nRead); PqhR^re0.
} %O=U|tuc$
catch(Exception e){e.printStackTrace ();} .o._`"V
} h !yu. v
} [i&EUvo
- s}
s\CZ os&
//打印回应的头信息 A$H;2T5N
public void logResponseHead(HttpURLConnection con) Q^|ZoJS
{ I 19 /
for(int i=1;;i++) WPN4mEow
{ D<DSK~
String header=con.getHeaderFieldKey(i); ^~iFG+g5
if(header!=null) tz).]E D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8c6dTT4
Utility.log(header+" : "+con.getHeaderField(header)); qir/Sa'[
else s"7$SxMT
break; OrZ=-9"
} 0G=bu5
} uaX#nn?ws
^uDNArDmj5
OIqisQ7ZB
public void splitterStop() CXe2G5
{ C`++r>
bStop = true; _gGI&0(VM
} I"4Lma
f4h|Nn%;
2NNAsr}L
} 24}?GO
S~ff<A>f
|3a1hCxt
/* Dm")\"5\?
**FileAccess.java _N-.=86*
*//文件访问(定位，写) !bPsJbIo>
package NetFox; gcy'"d"
import java.io.*; B*zR/?U^
l$1z%|I
(D?%(f
public class FileAccessI implements Serializable{ 4F-r}Fj3
BeNH"Y:E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Gl4(-e'b
RandomAccessFile oSavedFile; ek^=Z`
long nPos; <8JV`dTywC
em@bxyMm
o)(N*tC
public FileAccessI() throws IOException P?zPb'UVqa
{ w6-A-M6hD
this("",0); V[w Y;wj
} %y{f]m
':mw(`
T~238C{vh
public FileAccessI(String sName,long nPos) throws IOException o9j*Yz
{ [\Ks+S
oSavedFile = new RandomAccessFile(sName,"rw"); &yQilyU{V
this.nPos = nPos; 4)cQU.(*k
oSavedFile.seek(nPos); XMR$I&;G8
} w;=fi}<G|e
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[32]wgw+{1
public synchronized int write(byte[] b,int nStart,int nLen) |<Cz#| ,q
{ 3k#?E]'
int n = -1; ae&i]K;
try{ TIs~?wb$
oSavedFile.write(b,nStart,nLen); HB>&}z0
n = nLen; ir72fSe
} yR`X3.:*]
catch(IOException e) 9L`5r$/
{ c"pI+Q
e.printStackTrace (); z vM=k-Ec
} ]YO &_#
]ZkR~?
<~%e{F:[#
return n; ,C=Lu9
} sULCYiT|Hn
g}cb>'=={
#[Z1W8e
} (P+TOu-y\
sQ)D.9\~
8RA]h?$$J
/* H}Jdnu|ko
**SiteInfoBean.java &gP/<!#
*/ *an^ 0
package NetFox; yFD3:;}
3U_-sMOB|
,n}h_ct
public class SiteInfoBean { ~x!"(
d4 Hpe>
Wk0"U V
private String sSiteURL; //Site's URL p)dD{+"/2
private String sFilePath; //Saved File's Path 3@t&5UjwQ
private String sFileName; //Saved File's Name )&nfV5@"
private int nSplitter; //Count of Splited Downloading File GG9YAu
$$,/F
lBYc(cr
public SiteInfoBean() H}nPaw]G
{//nSplitter的缺省值为5 F+c4v A})
//default value of nSplitter is 5 H*gX90{!2
this("","","",5); Z4"SKsJT/>
} 65P*Gu?
Ib~n}SA
*VbB'u:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o_(@v2G`
{ c2tf7fkH
sSiteURL= sURL; ^57G]$Q
sFilePath = sPath; V5.=08L
sFileName = sName; 2;v1YKY
this.nSplitter = nSpiltter; cC NyW2'
k3 YDnMRA9
bh[`uRC}
} bzl-|+!yB
z;VAi=m q
7,.3'cCL^
public String getSSiteURL() e"){B
{ B@8M2Pl
return sSiteURL; -MCDX^>P
} wWaJ%z>3y
K[.*8
o>#ue<Bc6
public void setSSiteURL(String value) "B$r{ vG
{ =vpXYj
sSiteURL = value; d'x'hp%
} wa)E.(x
(>LJv |wn
oZ/z{`
public String getSFilePath() /^2&@P7
{ wT taj08D
return sFilePath; A#&,S4Wi|
} 4P>4d +
Dh4EP/=z
'X$J+s}6&
public void setSFilePath(String value) si!jB%^
{ &4dh$w]q
sFilePath = value; 'Avp16zg
} qubyZ8hx
S5,y!K]C~
< s>y{e
public String getSFileName() cl'#nLPz;
{ [yEH!7
return sFileName; C{5bG=Sg~
} R9!GDKts%
; xz}]@]Ar
Yp;6.\Z8[
public void setSFileName(String value) k*U(ln
{ ,drcJ
sFileName = value; tn\PxT
} ;7HL/-
C<T)'^7z
w.:fl4V
public int getNSplitter() =Qf.
{ QMI6l'"s
return nSplitter; $Y\-X<gRH
} Y\e8oIYu7
Q!T+Jc9N
G<MX94?
public void setNSplitter(int nCount) v5/2-<6x
{ "Q[rM1R
nSplitter = nCount; b}C6/zW
} CZ~%qPwDw
} $3BH82
V+Tu{fFF7E
\nKpJ9!
/* m,qMRcDF
**Utility.java 0&W*U{0F\
*/ x,+2k6Wn!
package NetFox; )M:pg%
zDD1EycH
SXJ]()L?[v
public class Utility { (c'kZ9&
T``O!>J
v=Y) A?
public Utility() 5>nbA8
{ `\]gNn'Q
jkrv2 `"
jx?"m=`s:
} "fq8)
$7'K]'UJXO
//线程睡眠 kuZs30^
public static void sleep(int nSecond) ]6*+i$
{ }23#z
try{ -!s?d5k")
Thread.sleep(nSecond); WS7a]~3'
} 4b}94e@(N
catch(Exception e) rmq^P;At
{ ;"1
e.printStackTrace (); Di^7@}kQS
} H*H=a
} _-mJI+^/
]CnqPLqL
//日志 -:P`Rln
public static void log(String sMsg) E979qKl
{ $YPQi.
System.err.println(sMsg); x392uS$#
} jWX^h^n7K
G^6\OOSy
D$vP&7pOr4
public static void log(int sMsg) \U\k$ (
{ 7Gs0DwV
System.err.println(sMsg); ;/-X;!a>
} K;NaiRP#k
} N =0R6{'
F,NS:mE
q_gsYb
/* ,<cF<9h
**TestMethod.java &#w~S~
*/ '-?t^@
package NetFox; q@6Je(H
wfJ[" q
z"*$ .
public class TestMethod { WokQ X"
k@RIM(^t
%CaUC'
public TestMethod() }2;{}J
{ ///xx/weblogic60b2_win.exe D_(K{?KU
try{ 1}#RUqFrvS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); km[PbC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d$O)k+j
SiteFileFetch fileFetch = new SiteFileFetch(bean); [-pB}1Dxb
fileFetch.start(); $At,D.mGkb
} }aJK^>^>A
catch(Exception e){e.printStackTrace ();} xdV $dDCT
!arTR.b\
6z2_b wo
} eCI0o5U
>RL|W}tI4
/U1 jCLR'
public static void main(String[] args) J]=2] oI2
{ w?db~"T
new TestMethod(); >8>}o4Q/X
} X"z!52*3]
} 7K\H_YY8#
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