社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 8125阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* |1iCt1~U  
**SiteFileFetch.java )u)]#z  
*/ jq#uBU %  
package NetFox; i"V2=jTeBv  
import java.io.*; ? BtWM4Id8  
import java.net.*; !Bcd\]q  
]A+q:kP  
f?}~$agc  
public class SiteFileFetch extends Thread { o&g-0!"  
~"6/OJA  
\D}K{P  
SiteInfoBean siteInfoBean = null; //文件信息Bean 'mx_]b^O  
long[] nStartPos; //开始位置 *.nC'$-2r  
long[] nEndPos; //结束位置 c((^l&  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 nG hFYQl  
long nFileLength; //文件长度 " lar~  
boolean bFirst = true; //是否第一次取文件 _1 TSt%L  
boolean bStop = false; //停止标志 sq1Z;l31"  
File tmpFile; //文件下载的临时信息 k<x  %  
DataOutputStream output; //输出到文件的输出流 fbgq+f`\  
c 4xh  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) [ }-CXB  
public SiteFileFetch(SiteInfoBean bean) throws IOException oNH&VHjU  
{ ~Y]*TP  
siteInfoBean = bean; BiI?eT +  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); O%?noW  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); t_%6,?S6  
if(tmpFile.exists ()) A& u"NgJ  
{ 1<g,1TR  
bFirst = false; /|v:$iH,C  
read_nPos(); Q%:#xG5AmE  
} Sg;c|u  
else S,A\%:Va  
{ s"G;rcS}#  
nStartPos = new long[bean.getNSplitter()]; l;_zXN   
nEndPos = new long[bean.getNSplitter()];  (o`"s~)  
} ,-,BtfE3  
?+EN.P[;3  
eTVI.B@p  
N4y$$.uv2  
} M8j%bmd(,  
$$QbcnOf$  
X$z@ *3=  
public void run() Byq4PX%B  
{ LU "e9  
//获得文件长度 9*wS}A&Jh  
//分割文件 gQHE2$i>  
//实例FileSplitterFetch c}(fmJB&(  
//启动FileSplitterFetch线程 ,2hZtJ<A  
//等待子线程返回 mNUc g{ +/  
try{ g_{hB5N](7  
if(bFirst) Ewg5s?2|  
{ A#t#c*  
nFileLength = getFileSize(); ,jVj9m  
if(nFileLength == -1) =pHWqGOD  
{ p<hV7x-{  
System.err.println("File Length is not known!"); P){F2&!P  
} eTi r-7  
else if(nFileLength == -2) {p#[.E8  
{ GR&T Z   
System.err.println("File is not access!"); -UgD  
} 5<1,`Bq@  
else =+@IpXj  
{ 5 \1C@d  
for(int i=0;i<nStartPos.length;i++) B1\@ n$  
{ W '54g$T  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2x3'm  
} CYlZ<W'  
for(int i=0;i<nEndPos.length-1;i++) GMLDmTV  
{ Mx& P^#B3  
nEndPos = nStartPos[i+1]; pC9Ed9uRK  
} -8F~Tffx  
nEndPos[nEndPos.length-1] = nFileLength; }*0OLUFFJ  
} L_$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  
((Bu Bu>  
d9/YW#tm  
while(!bStop) Y)% CxaO `  
{ !Pmv  
write_nPos(); )KvQaC  
Utility.sleep(500); m*VM1kV  
breakWhile = true; 1EW-%GQO  
Umwd <o  
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`$V(>&  
} 'ad|@Bh  
catch(Exception e){e.printStackTrace ();} Jt4T)c9  
} c9e  }P  
dO Y+| P\  
ye U4,K o  
//获得文件长度 )4[{+OJa  
public long getFileSize() [MM11K  
{ h~$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$g  
(bo{vX  
hB:R8Y^?H  
String sHeader; Rk fr4  
8<u_ wt@  
~S Js2- 2  
for(int i=1;;i++) 6 USet`#  
{ BzH7E[R49  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ih1s`CjG  
//Utility.log(in.readLine()); [_j.pMH/P  
sHeader=httpConnection.getHeaderFieldKey(i); FE1dr_i  
if(sHeader!=null) ,2?"W8,  
{ DSix(bs9  
if(sHeader.equals("Content-Length")) M3 8,SH<  
{ n15c1=gs  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z x{\SU  
break; Qwx}e\=  
} hD\C[C,  
} Cm}ZeQ  
else 5}e-~-  
break; lqPRUkin  
} "z^Ysvw&~  
} NW=j>7  
catch(IOException e){e.printStackTrace ();} LJZEM;;}  
catch(Exception e){e.printStackTrace ();} {Z;W|w1t  
\`x'r$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]; XrSqU D  
for(int i=0;i<nStartPos.length;i++) l W&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=~c x  
C UBcU  
]iLfe&f  
} Iob o5B  
} @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"  
$8i t&/JP,  
]s, T` (&  
String sURL; //File URL O gHWmb  
long nStartPos; //File Snippet Start Position |Ca$>]?  
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 _5 y)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 (); ^u Z%d  
httpConnection.setRequestProperty("User-Agent","NetFox"); @&M $`b ^  
String sProperty = "bytes="+nStartPos+"-"; hZzsZQ`  
httpConnection.setRequestProperty("RANGE",sProperty); .2Rh_ful  
Utility.log(sProperty); \-sD RW  
$~ItT1k_  
!4z"a@$  
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{$c b"5  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `pcjOM8u  
{ 6(ja5)sn*  
nStartPos += fileAccessI.write(b,0,nRead); hR{Fn L  
//if(nThreadID == 1) }:hdAZ+z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u-k*[!JU  
} sHEISNj/^  
d0N7aacY  
yr;oq(&N  
Utility.log("Thread " + nThreadID + " is over!"); /D~ ,X48+  
bDownOver = true; #vS>^OyP  
//nPos = fileAccessI.write (b,0,nRead); 3d,|26I7f  
} iWtWT1n8n  
catch(Exception e){e.printStackTrace ();} E|^a7-}|  
} 9'4cqR  
} ]q?<fEG2<  
St(7@)gvY  
s}HTxY;  
//打印回应的头信息 8o4 vA,  
public void logResponseHead(HttpURLConnection con) 0q62{p7  
{ +5T0]!  
for(int i=1;;i++) 6xj&Qo  
{ >)VrbPRuA  
String header=con.getHeaderFieldKey(i); 2&Efqy8}DZ  
if(header!=null) ~^3B(feQ]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s'K0C8'U  
Utility.log(header+" : "+con.getHeaderField(header)); +"d{P,[3J  
else I.( 9{  
break; =RQ>q  
} K): )bL(B  
} 7tt&/k?Q  
#D}NT*w/  
rP>5OLP  
public void splitterStop() ^Nc\D7( l  
{ 4Q!*h8O  
bStop = true; Ig9$ PP+3  
} ^,`yt^^A  
I=lA7}  
*J%+zH  
} q&P"  
R a 9/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| $c  
O"{NHNG\oT  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rgOB0[  
RandomAccessFile oSavedFile; 2p'qp/  
long nPos; <K2 )v~  
fHe3 :a5+W  
7ZJYT#>b  
public FileAccessI() throws IOException fw-LZ][  
{ Pw+cpM 8<  
this("",0); 7DT9\BT  
} o{ U= f6  
LdRLKE<'e  
="XxS|Mq3  
public FileAccessI(String sName,long nPos) throws IOException Q+#, VuM  
{ G:A` n;E0  
oSavedFile = new RandomAccessFile(sName,"rw"); uS<&$J H  
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  
08cC rG  
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$N5  
public String getSSiteURL() lE'2\kxI?  
{ /*i[MB  
return sSiteURL; ?s6v>#H%  
} ?sk{(UN]  
Y2W|b5  
Ja"?Pb  
public void setSSiteURL(String value) yxik`vmH  
{ U]ynnw4  
sSiteURL = value; }&F|u0@b  
} lvY[E9I0  
W2&o'(P\  
 6g576  
public String getSFilePath() +<a-;e{  
{ _<qe= hie!  
return sFilePath; #~BsI/m  
} whxTCIV  
.J"QW~g^  
DS%~'S  
public void setSFilePath(String value) n 9PYZxy  
{ 0*]n#+=  
sFilePath = value; x+EkL3{  
} Je5}Z.3m  
u5;;s@{Ye4  
q HaH=g%  
public String getSFileName() @IhC:Yc  
{ lE'3UqK  
return sFileName; J}BN}|Y@2  
} X6 *4IE  
<hvs{}TS  
Ra) wlI x  
public void setSFileName(String value) >J*x` a3Q  
{ ct`j7[  
sFileName = value; rP|~d}+I  
} %D1 |0v8}  
Swa0TiT(  
Ql"kJ_F!br  
public int getNSplitter() )0+6^[Tqq  
{ 0Q?)?8_  
return nSplitter; `%;Hj _X}  
} KW-GVe%8f  
/o OZ>B%1s  
E@,m +  
public void setNSplitter(int nCount) N,W ?}  
{ 'HKDGQl`  
nSplitter = nCount; z36wWdRa6  
} GXC,p(vbE  
} YLJ^R$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)  
P 0e-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 +$  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
10+5=?,请输入中文答案:十五