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)); |)VNf.aJZ
} HPMj+xH
for(int i=0;i<nEndPos.length-1;i++) uG7?:) pxv
{ d\ I6Wn
nEndPos = nStartPos[i+1]; sU(<L0
} bvW3[ V
nEndPos[nEndPos.length-1] = nFileLength; ;fW`#aE
} VTUSM{TC
} A$g'/QM
buldA5*!o
lY&Sx{-
//启动子线程 d>gQgQ;g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; enGZb&
for(int i=0;i<nStartPos.length;i++) (`&SV$m
{ .[r1Qz7G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /HH_Zi0?N|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QE|x[?7e,!
nStartPos,nEndPos,i); A("\m>g$b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kQF3DR$,B
fileSplitterFetch.start(); x)jc
} C2CR#b=)i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +~>cAWZq_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NQxx_3*4O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e?7y$H-
nEndPos = " + nFileLength); eZ]>;5
// fileSplitterFetch[nPos.length-1].start(); XU<XK9EA
@Q7^caG
:q>)c]
//等待子线程结束 }hE!0q~MfM
//int count = 0; ;qO3m-(d
//是否结束while循环 75pn1*"gQ
boolean breakWhile = false; % *ng *
d\R "?Sg
0Bt>JbGs4
while(!bStop) wV\7
{ N1}r%!jk/
write_nPos(); DUSQh+C
Utility.sleep(500); NFyV02.
breakWhile = true; PWeWz(]0Z4
xS(VgP&YGO
i[4!% FxB
for(int i=0;i<nStartPos.length;i++) z6Fl$FFP
{ K8/jfm
if(!fileSplitterFetch.bDownOver) ~|[i64V<^
{ U'^ G-@
breakWhile = false; T_qM@/f
break; Pv=]7>e
} !3<b#QAXRG
} Aj]/A
if(breakWhile) 'pyIMB?x
break; '[HBKn$`
>7)QdaB
V["'eJA,,
//count++; /oZvm
//if(count>4) XI:+EeM?
// siteStop(); ~]24">VZf
} nI4oQE
.AQTUd(_
;s#I b_
System.err.println("文件下载结束！"); PdEPDyFkh
} -aLM*nIoe
catch(Exception e){e.printStackTrace ();} AQtOTT$
} AHMvh 7O?
mq}UUk@
O3?^P"C
//获得文件长度 Lr20xm
public long getFileSize() %__ @G_M
{ Y O|hwhe_
int nFileLength = -1; oB@)!'
try{ FRL;fF
URL url = new URL(siteInfoBean.getSSiteURL()); c(29JZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oGyoU#z#
httpConnection.setRequestProperty("User-Agent","NetFox"); I?nU+t;
mKE'l'9A_
V lkJ$f5l
int responseCode=httpConnection.getResponseCode(); ]T(qk
if(responseCode>=400) {MN6JGb|'
{ vXZP>
processErrorCode(responseCode); V3T.EW
return -2; //-2 represent access is error Q);}1'c
} w11L@t[5W8
ny!80I
d|`8\fq
String sHeader; @\:@_}Z`_}
/cVZ/"
TwF.UL@G%
for(int i=1;;i++) OlptO60{ ]
{ >)Bv>HM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [g}0.J`_
//Utility.log(in.readLine()); :T>OJ"p
sHeader=httpConnection.getHeaderFieldKey(i); 5Q:49S47
if(sHeader!=null) f+.sm
{ :c Er{U8
if(sHeader.equals("Content-Length")) HX,i{aWWy
{ w_;$ahsu~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b\kA
break; sHV?njZd
} "\]]?&
} bYX.4(R
else ZN&9qw*
break; jK%Lewq
} RE-y5.kE^
} gKmF#Z"\
catch(IOException e){e.printStackTrace ();} &" 5Yt&{
catch(Exception e){e.printStackTrace ();} hBifn\dFr
'Q=(1a11
DeeV;?:
Utility.log(nFileLength); }AiF 7N0
ka{!' ^
T.B7QAI. H
return nFileLength; 5^CWF|
} 9+8N-LZ
oMYZ^b^
g5x>}@ONq7
//保存下载信息（文件指针位置） OB^j b8
private void write_nPos() PCa0I^d
{ 3Tc90p l*t
try{ 1zCgPiAem
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8o).q}>&
output.writeInt(nStartPos.length); cK\?wZ| Y
for(int i=0;i<nStartPos.length;i++) -D1A
{ o{l]n*
// output.writeLong(nPos); jR+kx:+
output.writeLong(fileSplitterFetch.nStartPos); ?iamo.0zN
output.writeLong(fileSplitterFetch.nEndPos); 6(Ntt
} V^>< =DNE
output.close(); xJFcW+
} {h.j6
catch(IOException e){e.printStackTrace ();} 64<*\z_
catch(Exception e){e.printStackTrace ();} 5Q8s{WQ
} n;:C{5
:2XX~|
ta'wX
//读取保存的下载信息（文件指针位置） 6?JvvS5
private void read_nPos() S0LaQ<9.
{ *<h)q)HS
try{ 8.7lc2aX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }KNBqPo4B
int nCount = input.readInt(); 2p58_^l
nStartPos = new long[nCount]; qagR?)N)u
nEndPos = new long[nCount]; <7gv<N6BQf
for(int i=0;i<nStartPos.length;i++) ;hEeFJ=/G
{ [8Z !dj
nStartPos = input.readLong(); glBS|b$\:
nEndPos = input.readLong(); nV8iYBBym
} IP)%y%ycw
input.close(); 8,e%=7h_e
} <,U$Y>
catch(IOException e){e.printStackTrace ();} j6L(U~%
catch(Exception e){e.printStackTrace ();} 8kE3\#);\
} =Tfm~+7nE
c'5ls7?}O{
WYkh'sv >
private void processErrorCode(int nErrorCode) !!cN4X
{ mrr -jo
System.err.println("Error Code : " + nErrorCode); "g!ek3w(
} .SNg2.
C\^,+)Y\~
rfr]bq5
//停止文件下载 M)H*$!x}>
public void siteStop() {A)9ePgv!
{ 'q@vTM'-
bStop = true; <\P `<
for(int i=0;i<nStartPos.length;i++) vskp1Wi(
fileSplitterFetch.splitterStop(); VSh&Y_%
iqN?'8
QFgKEUNgl
} k^zU;
} k)W&ZY
//负责部分文件的抓取 Ynp#3r
**FileSplitterFetch.java Vjd>j; H
*/ y! QYdf?
package NetFox; P?zaut
W! J@30
8xkLfN|N=
import java.io.*; uf"(b"N0
import java.net.*; 'ud[#@2
io@f5E+?
wzBw5nf\
public class FileSplitterFetch extends Thread { wyXQP+9G
J"TF@7{p
bfy=
String sURL; //File URL x0)WrDb
long nStartPos; //File Snippet Start Position % iZM9Q&NC
long nEndPos; //File Snippet End Position aK 3'u
int nThreadID; //Thread's ID tf[)| /M
boolean bDownOver = false; //Downing is over G&"O)$h
boolean bStop = false; //Stop identical p./0N.
FileAccessI fileAccessI = null; //File Access interface ;WgUhA ;q
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?/myG{E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G.PRPl
{ NOKU2d4 G
this.sURL = sURL; JV_VM{w{K
this.nStartPos = nStart; 0sTR`Xk
this.nEndPos = nEnd; Xg*](>/\,
nThreadID = id; mkl^2V13~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \N$)Q.M
} $g/h=w@
sRqecG(n
0?dr(
public void run() NCl@C$W9q
{ s[t<2)i
while(nStartPos < nEndPos && !bStop) 90K&oof?M
{ ?Ygd|a5
./L)BLC i
MH9vg5QKp
try{ )4m`Ya,E3
URL url = new URL(sURL); Ivj=?[c|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8m=O408Q
httpConnection.setRequestProperty("User-Agent","NetFox"); l5\V4
String sProperty = "bytes="+nStartPos+"-"; ga(k2Q;y
httpConnection.setRequestProperty("RANGE",sProperty); '$?!>HN4
Utility.log(sProperty); KSHq0A6/q%
`uH7~ r^
[m%]C
InputStream input = httpConnection.getInputStream(); DUh\x>^
//logResponseHead(httpConnection); b6p'%;Y/
b4WH37,lA
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byte[] b = new byte[1024]; JodD6;P
int nRead; F=e-jKogK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $*T?}r>
{ x0:BxRx*
nStartPos += fileAccessI.write(b,0,nRead); $mh\`
//if(nThreadID == 1) c&FOt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v^vi *c
} Ip:54
Poa&htxe1
c+ByEP4EG
Utility.log("Thread " + nThreadID + " is over!"); VpSpj/\m)'
bDownOver = true; ^$sqU
//nPos = fileAccessI.write (b,0,nRead); bI8uw|c
} ,v,rY'
catch(Exception e){e.printStackTrace ();} 0;=-x"
} >#k- ~|w
} |_>^vW1f
RAP-vVh/C
Qh(X7B
//打印回应的头信息 e}S+1G6r)
public void logResponseHead(HttpURLConnection con) j49Uj}:j
{ A`ajsZ{q,
for(int i=1;;i++) ^|]Dg &N.
{ q!?*M?Oz
String header=con.getHeaderFieldKey(i); K +3=gBU*w
if(header!=null) _lFw1pa#\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oPM*VTMA
Utility.log(header+" : "+con.getHeaderField(header)); 8/BMFRJ
else P(TBFu
break; V3cKbk7~
} {svo!pN:
} IT&,?u%
T9H*]LxK
3m`>D e
public void splitterStop() 2R.LLE
{ Zo yO[#
bStop = true; _gI1rXI
} hW<v5!,
I4{xQI
z+yIP ?s}(
} ;ryNfP%
&Xqxuy ]J
ElV!C}g
/* rUj\F9*5#
**FileAccess.java *_o(~5w-K
*//文件访问(定位，写) '=n?^EPE3
package NetFox; |uqI}6h.
import java.io.*; 6!\V|
uy{O
@+b$43^
public class FileAccessI implements Serializable{ `MI\/oM@
W=+n|1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xt^1,V4Ei~
RandomAccessFile oSavedFile; RE>Q5#|c
long nPos; ;'S,JGpvT
\zBi-GI7
#X-C~*|>j
public FileAccessI() throws IOException >(RkoExO/
{ ojM'8z0Hn
this("",0); .LDZqWr-
} :r q~5hK
S_P&Fv
50_[hC&C)
public FileAccessI(String sName,long nPos) throws IOException HMd?`
{ ;M~,S^U
oSavedFile = new RandomAccessFile(sName,"rw"); Nf]?hfJ
this.nPos = nPos; v@\S$qU2
oSavedFile.seek(nPos); KhR3$|fH<
} =yod
poQ_r<I
q;eb
public synchronized int write(byte[] b,int nStart,int nLen) EH844k8 p
{ MLd;UHU
int n = -1; |Hf|N$
try{ }097[-g7
oSavedFile.write(b,nStart,nLen); ~@'wqGTp
n = nLen; m9[ 7"I
} Y<T0yl?
catch(IOException e) S`s]zdUTP
{ mx9vjWfy
e.printStackTrace (); l[E^nh>
} fu!T4{2
v2x+_K}J
q1rj!7
return n; sQgz}0_=)
} l#[Z$+!09
IHEbT
KdoI
} :?xH)J,imk
$@Vn+| Ix
# xO PF9
/* GN_L"|#)=
**SiteInfoBean.java _[[0rn$
*/ Htgo=7!?\3
package NetFox; mu\1hKq;B
aU6l>G`w
*}]#E$
public class SiteInfoBean { BH'*I yv
Oi\ s
ST{Vi';}
private String sSiteURL; //Site's URL ,7wYa&
private String sFilePath; //Saved File's Path 7^i7U-A<A
private String sFileName; //Saved File's Name WWpMuB_G
private int nSplitter; //Count of Splited Downloading File ZLzc\>QX
=2$( tXL
n3p@duC4
public SiteInfoBean() 1{N+B#*<[X
{//nSplitter的缺省值为5 CU|E-XPW
//default value of nSplitter is 5 LzL)qdL
this("","","",5); O[d#-0s
} !H\;X`W|~D
AFi_P\X
O+W<l:|$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n$2oM5<
{ *)RKU),3nL
sSiteURL= sURL; nT?+^Ruc
sFilePath = sPath; /xUF@%rT
sFileName = sName; _;3,
this.nSplitter = nSpiltter; ,ciX *F"
,\i*vJ#f
\Vme\Ke*v)
} ]EHsRd
jSpj6:@B
6rnFXZ\
public String getSSiteURL() 2-@)'6"n
{ Movm1*&=
return sSiteURL; -+[Lc_oNPx
} c>$d!IKCL
HrE,K\^
{ENd]@N*
public void setSSiteURL(String value) A8tJ&O rwY
{ }<~(9_+
sSiteURL = value; (d#&m+ g]
} Jk%5Fw0
XQ=%a5w
l)\Q~^cxd
public String getSFilePath() x_~_/&X5
{ _]@u)$
return sFilePath; .I>rX#aNt
} K+|XI|1p
/)kJ iV
O1~7#nJ*4[
public void setSFilePath(String value) IoLP*D
{ CJk"yW[,|
sFilePath = value; VLV]e_D6s
} |yz[mP*;o
Pd+*syOM
CmXLD} L_x
public String getSFileName() O#k; O*s'
{ >>$L vQ
return sFileName; cO]w*Hti
} b_`h2dUq
hqln6m
Pm6U:RL
public void setSFileName(String value) C7F\Y1Wj
{ :@)R@. -
sFileName = value; K6-)l isf
} "8%$,rG1&
@k{q[6c2n
o@N[O^Q V
public int getNSplitter() Dl.UbH }=
{ 5wW5 n5YS
return nSplitter; bM"?^\a&Q
} @?e~l:g})g
cz,CL/rno
?{aC-3VAT
public void setNSplitter(int nCount) :[+8(~| za
{ 5eL b/,R
nSplitter = nCount; g4k3~,=D3
} ;%d<Uk?
} 2FaCrc/
m#_Rv
E`.hM}h
/* =v^#MU{k?
**Utility.java YvN]7tcb
*/ $)@D(m,ybd
package NetFox; S'^ q
FRR05%K
=PY{Elf
public class Utility { qE2VUEv5Y
iJE:>qOTD5
?o.d FKUe
public Utility() ~tWh6-:|{J
{ OU.}H $x"
sgP{A}4 W
~}j+~
} G=[<KtWa
O>+=cg
//线程睡眠 y akRKiz\
public static void sleep(int nSecond) o}G`t Bz
{ , @UOj=
try{ n_; s2,2r
Thread.sleep(nSecond); *]HnFP
} TW>GYGz
catch(Exception e) ?2#'>B
{ [m{sl(Q
e.printStackTrace (); ~IW{^u
} G\F>*
} 66F?exr
U!-Nx9
//日志 :,JjN&
public static void log(String sMsg) Z5(9=8hB/
{ hsY?og_H
System.err.println(sMsg); o/7u7BQl2
} XfE9QA[
@:Zk,
9h6Oq(0b8
public static void log(int sMsg) u$^tRz9
{ N8pL2y:R[P
System.err.println(sMsg); p&RC#wYu
} G`n $A/9Q
} >nSt<e
Rs5lL-I
l90"1I A
/* LWJ ?p-X
**TestMethod.java \AroSy9
*/ cg3}33Z;6
package NetFox; 2lsUCQI;
1}a4AGAp
~5&4s
public class TestMethod { uEJ8Lmi
$Z7:#cZ Y
sUda
public TestMethod() -eYL*Pa
{ ///xx/weblogic60b2_win.exe ork|yj/A
try{ 7S2c|U4IM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,$i<@2/=m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SbJh(V-pr
SiteFileFetch fileFetch = new SiteFileFetch(bean); cX"G7Bh
fileFetch.start(); _&mc8ftT
} Z`"n:'&
catch(Exception e){e.printStackTrace ();} Ey= 4 b
"sIN86pCs
(lWKy9eTy`
} [5pn@o
C!kbZTO[p"
\"bLE0~
public static void main(String[] args) @YrGyq
{ G%`cJdM
new TestMethod(); s|p(KWo2U
} (T2<!&0 @
} =KW|#]RB^
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